Question

An isosceles triangle has base angles that each measure 62°. Which equation can be used to find x, the measure of the third angle of this isosceles triangle in degrees?

A 124 + x = 180
B 124 + 2x = 180
C 62 + 2x = 180
D 62 + x = 180

Answer 1

Correct answer is A 124 + x = 180

Explanation:

The sum of three angles of an isosceles triangle is always 180.

If one base angle is 62° other is also 62 °. So if the third one is x, we get;

62 + 62 + x = 180

124 + x = 180

Answer 2

B. 124° + x = 180°

Explanation:

In an isosceles triangle, the two base angles are always equal.

Therefore, the sum of the two base angles in the isosceles triangle in the question is 2 × 62° = 124°.

The sum of the angles in any triangle is always 180°. Therefore, the equation that can be used to find the measure of the third angle of the isosceles triangle is:

124° + x = 180°

Therefore, the answer is B. 124° + x = 180°