Read the directions and answer the questions in the space provided.
1. Look at the figure. Find m<1 and m<3. Then, explain how their sum relates to the angle measuring 140° by completing the theorem.
140°/2
B
3\
159------~
mL2 = 180 -
m<3 = 180 -
m<1+ mL2 +m<3=180°
m<1+
= 180°
m<1 =
What is the sum mL1 + mL3?
Theorem: the measure of an exterior angle is equal to
