Question

A triangle has angles that measure 55°, 80°, and r. What is r?

Answer 1

R = 45°

Since the sum of the angles in a triangle is always 180°, we can find the measure of the third angle by subtracting the sum of the other two angles from 180°.

180 - (55+80) = 45

Answer 2

Answer: r = 45°

Explanation:

All triangles angles add up to 180 degrees.

With that said we can use the given information and create an equation to solve.

55° + 80° + r = 180°

Lets solve for r.

55° + 80° + r = 180°

first lets combine like terms.

135° + r = 180°

now lets subtract 143° from both sides

135° + r = 180°

-135° -135°

r = 45°