Question

What is the relationship between the base angles of an isosceles triangle? Explain.

The base angles are complementary because their sum is 90°.


The base angles are supplementary because their sum is 180°.


The base angles are adjacent to the legs of the triangle.


The base angles are opposite the congruent sides, and they are congruent by the Base Angles Theorem.

Answer 1

The base angles of an isosceles triangle are opposite the congruent sides, and they are congruent by the Base Angles Theorem.

Step-by-step explanation:

The Base Angle Theorem states that in an isosceles triangle, the angles opposite the congruent sides are congruent.

Answer 2

From the given, the true statements are,

• The base angles are adjacent to the legs of the triangle.

• The base angles are opposite the congruent sides, and they are congruent by the Base Angles Theorem.

Step-by-step explanation:

Isosceles triangle are the triangle which has two equal angles. The sides of the same angles are called legs of the angle. So other than the legs, the other side is called the base. Basically the angles between the base and the legs are same. These angles are called base angles.

Hence the Base angle theorem states that the base angles are always congruent.