Question

Find the measure of the missing angles.
m∠5

Answer 1

50

Explanation:

3 is the vertically opposite angle of 55 degrees, so angle 3 is also 55.

A triangle always adds up to 180 degrees, so you know that the other two angles together are (180-55) 125.

You can find angle 4 easily because of the 105 next to it. Both angles are along a straight line. Straight lines also always add up to 180 degrees. So if we already know 105, we can subtract it from 180 to find angle 4. We get 75.

So we know that 3 and 4 are 55 and 75 respectively. If we add those together (130) and subtract it from the total 180 degrees of the triangle (50), we can find the last angle.

So angle five is 50.