<2 = 39°. Find m<4 and explain how you know. Drawing not to scale.
1 answer
m<4 = 117°. This is because the angles in a triangle add up to 180°. Therefore, 180° - 39° = 141°. Since the two angles are equal, they must both be 141°/2 = 70.5°. Therefore, m<4 = 180° - 70.5° = 109.5°.