Question

One angle in an isosceles triangle measures 50°. Which of these cannot be the measure of an angle in this triangle? A 50 C 80% D130​

Answer 1

D

Explanation:

In an isosceles triangle two angles are equal to each other, single two sides are congruent. Since the sides of a triangle add up to 180, we can figure out possible answers. This means it could either be

50, 50 and 80

Or 50, 65, 65

Which means the impossible measure would be D 130.

Answer 2

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.