Quadrangles - Everyday Math
Transcription
Quadrangles - Everyday Math
Quadrangles Objective To provide opportunities to explore various types of quadrangles. o www.everydaymathonline.com ePresentations eToolkit Algorithms Practice EM Facts Workshop Game™ Teaching the Lesson Key Concepts and Skills • Identify right angles and parallel and intersecting sides of quadrangles. [Geometry Goal 1] • Draw and name quadrangles. [Geometry Goal 2] • Use straws and twist-ties to model and compare quadrangles. [Geometry Goal 2] • Identify the sides, vertices, and adjacent sides of quadrangles. [Geometry Goal 2] • Measure the sides of a quadrangle. [Measurement and Reference Frames Goal 2] Key Activities Children construct quadrangles and observe their properties. They measure the sides of a quadrangle to the nearest _12 inch and estimate the perimeter. Ongoing Assessment: Recognizing Student Achievement Family Letters Assessment Management Common Core State Standards Ongoing Learning & Practice 1 2 4 3 Playing Name That Number Student Reference Book, pp. 299 and 300 per partnership: 4 each of number cards 0–10 and 1 each of number cards 11–20 (from the Everything Math Deck, if available) Children practice finding equivalent names for numbers. Math Boxes 6 5 Math Journal 1, p. 137 Children practice and maintain skills through Math Box problems. Home Link 6 5 Math Masters, p. 177 Children practice and maintain skills through Home Link activities. Use journal page 136. [Geometry Goal 1] Ongoing Assessment: Informing Instruction Curriculum Focal Points Interactive Teacher’s Lesson Guide Differentiation Options READINESS Playing Touch-and-Match Quadrangles Math Masters, p. 467 (copied onto cardstock or cardboard) paper bag or box Children identify similarities and differences among quadrangles. ENRICHMENT Playing Shading Shapes Math Masters, pp. 457 and 458 Children explore the properties of quadrangles. ELL SUPPORT Adding to the Vocabulary Chart Differentiation Handbook, p. 133 (optional); 2 copies per child Vocabulary Chart (from Part 3, Lesson 6 1) Children add the terms rectangle, rhombus, square, trapezoid, and kite to the Vocabulary Chart. See pages 428 and 429. Key Vocabulary quadrangle square rhombus parallelogram sides kite rectangle trapezoid adjacent Materials Math Journal 1, p. 136 Student Reference Book, pp. 108 and 109 Home Link 64 Differentiation Handbook, p. 139 (optional) straws and twist-ties straightedge ruler Advance Preparation Each child will need 16 twist-ties and 16 straws—4 straws each of the following four lengths: 2", 4", 6", and 8". Place these materials in 4 separate containers near the Math Message. For the optional Readiness activity in Part 3, make 2 copies of Math Masters, page 467 on cardstock paper. Cut out the shapes and place one set in a paper bag. Teacher’s Reference Manual, Grades 1–3 pp. 136–138 426 Unit 6 Geometry 426_EMCS_T_TLG1_G3_U06_L05_576809.indd 426 2/23/11 11:45 AM Getting Started Mental Math and Reflexes Math Message Have children stand facing you to perform turn calisthenics. Take 4 straws of each size and 16 twist-ties. Complete Part 1 on page 136 of your journal. Make a half-turn clockwise. Make a half-turn counterclockwise. Ask: What do you notice? Children are back in the starting position. Make a three-quarter turn counterclockwise. Make a half-turn counterclockwise. Make a quarter-turn clockwise. Ask: What do you notice? Children are back in the starting position. Have girls make a three-quarter turn clockwise and boys make a quarter-turn counterclockwise. Ask: What do you notice? Girls and boys are facing in the same direction. Home Link 6 4 Follow-Up Ask partners to explain how they found the right angle in Problem 4. 1 Teaching the Lesson Math Message Follow-Up E WHOLE-CLASS DISCUSSION (Math Journal 1, p. 136) Discuss Part 1 on journal page 136. Draw and label a quadrangle on the board. Label it EFGH. Point out that another name for quadrangle is quadrilateral. Referring to the diagram on the board, review the characteristics of quadrangles. H G Quadrangle EFGH All quadrangles are 2-dimensional. All quadrangles have 4 vertices. Student Page All quadrangles have 4 sides. Date All quadrangles have 4 angles. Time LESSON Exploring Quadrangles 6 5 䉬 夹 Part 1 Adjusting the Activity ELL B Use a straightedge. Connect points to form a quadrangle. A Part 2 Remind children that the meaning of the prefix quad- is four. Ask for other words that use the prefix. Quadruplets, quadruple, quadrupled, quadrant, and quadrilateral (as another name for quadrangle) Draw or show pictures of a few of the objects children might suggest that have the prefix quad. Write all 4-letter names that are possible for your quadrangle. The first letter of each name is given below. A C BCD BAD A C DCB DAB B D CDA ABC B D D C ADC CBA Part 3 A U D I T O R Y K I N E S T H E T I C T A C T I L E Ongoing Assessment: Recognizing Student Achievement V I S U A L Journal page 136 Part 1 Work in a group. Make quadrangles with straws and twist-ties. Make at least one of each of the following kinds of quadrangles. 䉬 all 4 sides equal in length 䉬 2 pairs of equal-length sides, but opposite sides not equal in length 䉬 2 pairs of equal-length opposite sides 䉬 only 2 parallel opposite sides 䉬 only 1 pair of equal-length opposite sides Part 4 Measure each side of the quadrangle you drew in Part 1 to the nearest 1 ᎏᎏ centimeter. 2 Use journal page 136, part 1 to assess children’s progress toward identifying points and drawing line segments to form a quadrangle. Children are making adequate progress if they are able to successfully complete Part 1. Some children may be able to identify the vertices of the quadrangle. side AB 5ᎏ12ᎏ cm side BC 4 cm side CD 6ᎏ12ᎏ cm side DA 2 cm Try This The perimeter of my quadrangle is about 18 centimeters. [Geometry Goal 1] Math Journal 1, p. 136 Lesson 6 5 EM3cuG3TLG1_427-431_U06L05.indd 427 427 1/22/11 1:32 PM Student Page Geometry Naming Quadrangles Quadrangles A quadrangle is a polygon that has 4 sides. Another name for quadrangle is quadrilateral. The prefix “quad-” means four. All quadrangles have 4 sides, 4 vertices, and 4 angles. WHOLE-CLASS DISCUSSION (Math Journal 1, p. 136) A quadricycle is a vehicle similar to the bicycle and tricycle but having 4 wheels. Name the parts of the quadrangle. The sides are RS, ST, TU, and UR. The vertices are R, S, T, and U. The angles are R, S, T, and U. Some quadrangles have 2 pairs of parallel sides. These quadrangles are called parallelograms. Explain that the name of a quadrangle can begin with the letter at any vertex and can be read either clockwise or counterclockwise. Vertices must be named consecutively. For example, the quadrangle on the board can be named HEFG, EFGH, FGHE, and so on—but not HFGE. Have children complete Part 2 on journal page 136. Two sides are parallel if they are parts of lines that are parallel (never cross). Figures That Are Parallelograms Ongoing Assessment: Informing Instruction Opposite sides are parallel in each figure. Figures That Are NOT Parallelograms no parallel sides only 1 pair of parallel sides 3 pairs of parallel sides, but a parallelogram must have 4 sides Watch for children who have difficulty naming the quadrangle. Emphasize the importance of naming the vertices in order. Suggest that children trace the quadrangle with their fingers in order to determine the correct sequences. Student Reference Book, p. 108 Constructing Quadrangles (Math Journal 1, p. 136; Student Reference Book, pp. 108 and 109) NOTE Unlike triangles, quadrangles are not rigid. Their shapes and areas may easily be changed. But for any given quadrangle, the perimeter does not change and, for any given parallelogram, opposite sides remain parallel in spite of the changes to their inner angles. Student Page Geometry Some quadrangles have special names. Some of them are parallelograms. Others are not parallelograms. Quadrangles That Are Parallelograms Rectangles are parallelograms. They have 4 right angles (square corners). The sides of a rectangle do not all have to be the same length. Rhombuses are parallelograms. Their 4 sides are all the same length. Squares are parallelograms. They have 4 right angles (square corners). Their 4 sides are all the same length. All squares are rectangles. All squares are rhombuses. Quadrangles That Are NOT Parallelograms Trapezoids have exactly 1 pair of parallel sides. Their 4 sides can all be different lengths. Kites are 4-sided polygons with 2 pairs of equal sides. The equal sides are next to each other. Their 4 sides cannot all be the same length. A rhombus is not a kite because all 4 sides of the rhombus are the same length. others Any polygon with 4 sides that is not a parallelogram, a trapezoid, or a kite SMALL-GROUP ACTIVITY ELL PROBLEM PRO P R RO OB BLE BL LE L LEM EM SO S SOLVING OL O LV VIN IIN NG Children construct the quadrangles listed in Part 3 on journal page 136. Have children make their constructions on flat surfaces and keep them (approximately) in a plane as they pick them up to show them. When most of the groups have completed their constructions, bring them together to share observations about quadrangles. Children hold up quadrangles in each category as you and the class discuss their properties. To support English language learners as the geometric terms are introduced, write the terms on the board next to a picture or a straw model. Suggestions for discussion: Ask one person in each group to hold up any quadrangle with four sides of equal length and four right angles. Ask: How are all these quadrangles alike? They are all squares; their angles are all right angles. How are they different? They are not all the same size. Have children tug gently on two corners opposite each other. Ask: What happens when you do this? The shape and area change; the angles are not right angles, but the opposite sides are still parallel. Does the perimeter change? No What is the name of this shape? rhombus Have children make one angle a right angle. Ask: What happens when you do this? All angles become right angles. What is the name of this kind of shape? square Note that squares and rhombuses are examples of parallelograms. Student Reference Book, p. 109 428 Unit 6 Geometry EM3cuG3TLG1_427-431_U06L05.indd 428 1/20/11 8:43 AM Ongoing Assessment: Informing Instruction Watch for children who believe that squares are only squares and not rectangles or rhombuses. You may wish to make an analogy to address this misconception. For example, the girls in the classroom are students, daughters, citizens, and neighbors; they may also be sisters, granddaughters, or nieces. Likewise, the square also belongs to several groups. K Have children hold up quadrangles having two pairs of equal sides. Kites and rectangles From those quadrangles, find the ones that have right angles. Rectangles The quadrangles with two pairs of equal sides and 4 right angles are called rectangles. N Have children hold up quadrangles having only two parallel opposite sides. Trapezoids, which include those with one pair of equal-length sides Those quadrangles are called trapezoids. ● Can you make a trapezoid that has a right angle? Yes ● Can you make a trapezoid with exactly one right angle? Try it. No. If a trapezoid has one right angle, it must have a second right angle as well because opposite sides must be parallel. ● Can you make a trapezoid with four right angles? No. If a trapezoid had four right angles, it would be a rectangle. There would be two pairs of parallel sides instead of one. Sides that meet at a vertex are called adjacent sides. Have children hold up one of their quadrangles and trace its adjacent sides with their fingers. To support English language learners, write adjacent sides and draw some pictures illustrating adjacent sides on the board. Ask children in each group to hold up all quadrangles in which some or all adjacent sides are the same length. Have them set aside all the quadrangles in which all sides are the same length. Next, have them hold up any quadrangles in which there are just two pairs of equal adjacent sides. Such quadrangles are called kites. A kite is a quadrangle that has two pairs of equal adjacent sides and opposite sides that are not equal. To support English language learners, discuss the everyday meaning of the word kite as well as its meaning in this context. L M Kite Adjusting the Activity ELL Use a Venn diagram, Differentiation Handbook, page 139, to organize information about similarities and differences between 2 quadrangles. AUDITORY KINESTHETIC of ties e l per Pro ctang e aR 4 square corners TACTILE Properties of a Square 4 equal sides and 4 square corners VISUAL Pro p a R erties hom of bus 4 equal sides Finally, have children hold up straw constructions that do not have four right angles or two pairs of parallel sides. Trapezoids and kites Add one straw construction of each kind of quadrangle and its description to the Polygon Museum. Children can read more about quadrangles on pages 108 and 109 of the Student Reference Book. Finding the Perimeter of a Quadrangle INDEPENDENT ACTIVITY PROBLEM PRO P RO R OBL BLE B L LE LEM EM SO S SOLVING OL O LV VIIIN VIN NG (Math Journal 1, p. 136) Children complete Part 4 on journal page 136. Lesson 6 5 EM3cuG3TLG1_427-431_U06L05.indd 429 429 1/22/11 1:32 PM Student Page Date Time LESSON 2 Ongoing Learning & Practice Math Boxes 65 1. The grid is ONE. Shade 0.41 of 2. Circle the pair of lines that are the grid. parallel. Playing Name That Number Write the fraction that shows how much is shaded. 41 _ 100 0.41 = SMALL-GROUP ACTIVITY (Student Reference Book, pp. 299 and 300) 34 99 Children play Name That Number. See pages 299 and 300 in the Student Reference Book or Lesson 1-6 for directions. Encourage children to use as many cards and operations as they can to name the target number. 4. Draw a ray, . Draw a line _DO 3. Fill in the oval for the best answer. . segment, RE. Draw a line, MI The turn of the angle is 1 less than a _ 2 turn. 1 less than a _ 4 turn. 1 greater than a _ turn. 2 a full turn. D O R M E I 6. Complete. all equal in length. ⫻4 ⫼2 6 24 12 48 192 48 96 24 any square or rhombus square This shape is a or rhombus Math Boxes 6 5 100 167 168 5. Draw a shape with 4 sides that are (Math Journal 1, p. 137) Mixed Practice Math Boxes in this lesson are paired with Math Boxes in Lesson 6-7. The skill in Problem 6 previews Unit 7 content. . 109 INDEPENDENT ACTIVITY 200 201 Math Journal 1, p. 137 EM3MJ1_G3_U06_128-155.indd 137 2/10/10 1:18 PM Home Link 6 5 INDEPENDENT ACTIVITY (Math Masters, p. 177) Home Connection Children identify characteristics of familiar quadrangles using the terms equal, parallel, and right angles in their answers. 3 Differentiation Options Home Link Master Name Date HOME LINK READINESS Time Playing Touch-and-Match Quadrangles 65 Family Note 108 109 Please return this Home Link to school tomorrow. (Math Masters, p. 467) equal parallel right angles 1. Rectangle (Squares are special rectangles.) All angles are right angles parallel To provide experience with identifying similarities and differences among quadrangles, make two copies of Math Masters, page 467 on cardboard or cardstock paper. Cut out all of the quadrangles and place one set in full view on a table. Without children seeing, place one of the quadrangles from the other set in a bag or box. A child reaches inside the container, feels the shape without looking, and tries to find the matching shape from those on the table. . equal Pairs of opposite sides are length and in to each other. 2. Rhombus (Squares are also rhombuses.) All sides are equal in length. parallel Opposite sides are to each other. 3. Parallelogram (Squares and rhombuses are also parallelograms.) Opposite sides are equal Opposite sides are parallel in length. Ask children to explain how they made their matches. Expect responses like the following: “The shape I was holding had four square corners, but I knew it was the square and not the rectangle because all of the sides were the same length.” to each other. 4. Kite Opposite sides are not equal 5–15 Min Quadrangles Help your child complete the statements. A right angle is a square corner. Parallel sides are the same distance apart and will never meet. Opposite sides are directly across from each other. Adjacent sides meet at a vertex (corner). Fill in the blanks using the following terms: SMALL-GROUP ACTIVITY in length. Practice Solve. 5. 6 × 3 = 18 6. 12 =3×4 7. 6×6= 36 Math Masters, p. 177 EM3MM_G3_U06_167-205.indd 430 177 2/10/10 1:18 PM Unit 6 Geometry EM3cuG3TLG1_427-431_U06L05.indd 430 1/20/11 8:43 AM Game Master ENRICHMENT Playing Shading Shapes PARTNER ACTIVITY Name Time Shading Shapes Materials □ gameboard and Shading Shapes Reference Page (Math Masters, p. 458) Object To claim the most quadrangles 15–30 Min (Math Masters, pp. 457 and 458) Date Directions Players take turns. To further explore properties of quadrangles, have children play Shading Shapes. Directions are on Math Masters, page 457. When children have finished, have them share their strategies. SMALL-GROUP ACTIVITY ELL SUPPORT Adding to the 1. Shade one small triangle on the gameboard. 2. Players shade triangles to make quadrangles they see on the reference page. 3. When a player shades the final triangle of a quadrangle from the reference page, that player claims the quadrangle by tracing the shape with a finger and saying the name of the quadrangle. When a player claims a quadrangle, he or she scores a point and that quadrangle is no longer available to claim. 4. Finished quadrangles may overlap each other (the same small triangle may be colored twice), but no one can shade exactly the same quadrangle once it has been claimed. 5. The game ends when time runs out or when the gameboard is completely shaded. The winner is the player with the most points. 5–15 Min Vocabulary Chart (Differentiation Handbook, p. 133) To provide language support for geometry terms, have children add the terms rectangle, rhombus, square, trapezoid, and kite to the Vocabulary Chart. Children may also add the terms to their Math Word Banks using the template on Differentiation Handbook, page 133. See the Differentiation Handbook for more information. 457 Math Masters, p. 457 EM3MM_G3_U06_167-205.indd 457 2/10/10 2:25 PM Quadrangles (Quadrilaterals) parallelogram 2 pairs of parallel sides rectangle 2 pairs of equal sides; 4 right angles rhombus 4 equal sides; opposite sides parallel square 4 equal sides; 4 right angles trapezoid only 2 sides parallel; parallel sides not equal kite Game Master Name Date Time Shading Shapes Reference Page Shade triangles on the gameboard to make the following quadrangles: 2 pairs of adjacent equal sides; opposite sides not equal Rectangle Square Parallelogram Trapezoid py g g p Trapezoid Math Masters, p. 458 EM3MM_G3_U06_167-205.indd 458 2/10/10 Lesson 6 5 EM3cuG3TLG1_427-431_U06L05.indd 431 2:25 PM 431 1/22/11 1:32 PM