After finding the third angle of a right triangle if the measure of one of the angles is 25°, prove how you know the measure of third angle. a. The sum of the measures of a right triangle is 180°. You know that a right angle measures 90°. So, 180 – 90 – 25 = 55.
b. The sum of the measures of a right triangle is 180°. You know that a right angle measures 90°. So, 180 – 90 – 25 = 65.
c. The sum of the measures of a right triangle is 360°. You know that a right angle measures 90°. So, 360 – 90 – 25 = 245.
d. There is not enough information given to solve this problem.