Question

Explain how you find m∠3 if m∠5 = 130° and m∠4 = 70°. *

Answer 1

The required measure of angle 3 is 60°.

Explanation:

We are given to find the measure of angle 3 from the figure if

m∠5 = 130° and m∠4 = 70°.

Let the measure of angle 3 be x°.

From the figure, we note that

angle 5 is an exterior angle and angles 3 and 4 are two remote interior angles of the triangle.

We know that

the measure of an exterior angle to a triangle is equal to the sum of the measures of two remote interior angles.

So, we get

Thus, the required measure of angle 3 is 60°.