If ABC is obtuse, what are the restrictions on x? ∠

1.2-Measurement of Segments and Angles
Opener
Name all angles in the diagram
Definitions:
Acute Angle: An angle whose measure is greater than 0° and less than
90°
Right Angle: An angle whose measure is 90°
Obtuse Angle: An angle whose measure is greater than 90° and less
than 180°
Straight Angle: An angle whose measure is 180°
Ex 1
If ABC is obtuse, what are the restrictions on x?
Chapter 1 Page 1
Ex 2
If mABC=70, then find m1 and m 2.
Angles are measured in degrees. Each degree is divided into 60
minutes (') and each minute is divided into 60 (")
Ex 3
2
Convert 41  to degrees, minutes, and seconds.
5
Ex 4
Convert 6045' to degrees
Ex 5
37°42'13" + 27°31'24"
Chapter 1 Page 2
Ex 6
90° - 37°31'42"
Definitions:
Congruent Angles: Angles that have the same measure
Congruent Segments: Segments that have the same length
Clock Problems
Every hour the hour hand of a clock turns __________. Why??
Ex 7
Find the smaller angle formed by the hands of a clock at the following
times.
a) 4:00
b) 8:30
c) 9:40
Chapter 1 Page 3
c) 9:40
d) 5:15
Chapter 1 Page 4