Answer:
60
Explanation:
Exterior angle property:
Exterior angle of the triangle equals the sum of opposite interior angle.
4z + z + 10 = z + 50
5z + 10 = z + 50
Subtract 10 from both sides,
5z = z + 50 - 10
5z = z + 40
Subtract z from both sides,
5z - z = 40
4z = 40
Divide both sides by 4,
z = 40 ÷ 4
z = 10
Exterior angle = z + 50
= 10 + 50
= 60