Question

Mark is making a decoration for a rally, using a string of triangular strips. Each strip is an isosceles triangle when flattened out.

What is the measure of the third angle?

A) 35°

B) 40°

C) 45°

D) 50°

Answer 1

B) 40 because if you add the two angles at the bottom which are shown to be congruent, then subtract 180 from the sum of those two, then you are left with your answer

Answer 2

The measure of third angle is 40°

B is correct.

Explanation:

Mark is making a decoration for a rally, using a string of triangular strips. Each strip is an isosceles triangle when flattened out.

In figure, we are given the base angle is 70°

For isosceles triangle base angles are equal.

Two angle of a isosceles triangle are 70° and 70°

Let third angle of triangular strips be A

Using angle sum property of triangle ( sum of all three angles of a triangle is 180°)

A+70°+70°=180°

A=180-140 = 40°

Hence, The measure of third angle is 40°