9514 1404 393
Answer:
angle 1 = 76°
angle 4 = 45°
Explanation:
The relevant relations are ...
- vertical angles are congruent
- the sum of angles in a triangle is 180°
- a linear angle is 180°
- an exterior angle is equal to the sum of the remote interior angles
__
Angle 1 can be found using the fact that the sum of interior angles is 180°
∠1 +68° +36° = 180°
∠1 = 76° . . . . . . . . . . . . . subtract 104° from both sides
__
Finding angle 4 requires you know angle 3, which is a vertical angle to the one marked 65°. This means we have ...
∠3 +70° +∠4 = 180° . . . . . . the angles together form a linear angle
∠4 = 180° -70° -65° . . . . . . substitute 65° for ∠3
∠4 = 45°