Answer:
The measure of the indicated exterior angle is 110°
Step-by-step explanation:
Let us revise the rule of the exterior angle
In a triangle, the measure of an exterior angle at a vertex of the triangle equals the sum of the measures of the two opposite interior angles to this vertex.
We will use this rule to solve the question
∵ The ladder, the house, and the ground formed a right triangle
∵ The ladder's angle with the ground facing away from the house is
an exterior angle of the triangle
∵ The angles of measures 90° and 20° are its opposite interior angles
→ By using the rule above
∴ The measure of the exterior angle = 90° + 20°
∴ The measure of the exterior angle = 110°
∴ The measure of the ladder's angle with the ground facing away
from the house is 110°
∴ The measure of the indicated exterior angle is 110°
