Question

Two of the angles in a triangle measure 10° and 80°. What is the measure of the third
angle?

Answer 1

Explanation:

Lets third angle be x

or,10°+x+80°=180° ( sum of triangle )

or,90°+x=180°

or,x=180°-90°

or,x=90°

Answer 2

90°

Explanation:

All angles inside a triangle add up to 180 so:

180 - 10 - 80 = 90

Therefore, the 3rd angle is 90°