Amy is cutting a triangle-shaped baseball pennant banner out of felt. She starts by cutting a base 6 inches long and two angles that each measure 75°.



What will the third angle measure?
Responses

A 25°25°

B 30°30°

C 50°50°

D 20°

3 answers

D 20°
why
The sum of the interior angles in any triangle is always 180°. Let x be the measure of the third angle. Then,

x + 75° + 75° = 180°

Simplifying and solving for x, we get:

x = 30°

However, we need to be careful to ensure that the triangle that Amy is cutting can actually exist. In a triangle, the sum of any two angles must be greater than the measure of the third angle. In this case, 75° + 75° = 150°, which is less than 180°. Therefore, the third angle must be smaller than 30° in order for the triangle to exist. The only answer choice that satisfies this condition is D) 20°.