Isosceles Base Angles

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length.

Front

What are the base angles of an isosceles triangle?

Back

The base angles of an isosceles triangle are the angles opposite the two equal sides.

Front

What is the Isosceles Triangle Theorem?

Back

The Isosceles Triangle Theorem states that the angles opposite the equal sides of an isosceles triangle are also equal.

Front

How do you find the measure of the base angles in an isosceles triangle?

Back

To find the measure of the base angles, subtract the measure of the vertex angle from 180 degrees and divide by 2.

Front

What is the relationship between the angles in an isosceles triangle?

Back

In an isosceles triangle, the two base angles are equal, and the sum of all angles is 180 degrees.

Front

If one base angle of an isosceles triangle is 45 degrees, what is the measure of the vertex angle?

Back

The vertex angle would be 90 degrees, since 180 - 2(45) = 90.

Front

What is the SAS (Side-Angle-Side) congruence theorem?

Back

The SAS congruence theorem states that if two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, then the triangles are congruent.

Front

If two triangles have two sides of equal length and the included angle is equal, what can be concluded?

Back

The two triangles are congruent by the SAS theorem.

Front

What is the significance of congruent triangles in geometry?

Back

Congruent triangles have the same size and shape, which means their corresponding sides and angles are equal.

Front

How can you determine if two triangles are congruent using the SAS theorem?

Back

Measure two sides and the included angle of both triangles; if they are equal, the triangles are congruent.