One angle in an isosceles triangle measures 50°. Which of these cannot be the measure of an angle in this triangle?

Question

A. 50°

B. 65°

C. 80°

D. 130°

Answer 1

Hi Leah,

In an isosceles triangle, 2 of the angles are identical

sum of the 3 angles of a triangle is always 180

possibility 1 - 50 is one of the 2 identical angles

the 3 angles will be 50, 50, (180-50-50)

possibility 2 - 50 is not one of the 2 identical angles

the 3 angles will be 50, (180-50)/2, (180-50)/2

you can work out the above and see which answer is not the possible angle

Please let me know if you have further questions.