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°

The measure of third angle is 40°

B is correct.

Step-by-step 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°

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9