Isosceles Triangles (open ended)

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 legs of an isosceles triangle?

Back

The legs of an isosceles triangle are the two sides that are of equal length.

Front

What is the base of an isosceles triangle?

Back

The base of an isosceles triangle is the side that is not equal in length to the other two sides.

Front

What are the base angles of an isosceles triangle?

Back

The base angles of an isosceles triangle are the angles opposite the legs, which are equal in measure.

Front

How many sides of an isosceles triangle are equal in length?

Back

Two sides of an isosceles triangle are equal in length.

Front

What is the vertex angle of an isosceles triangle?

Back

The vertex angle of an isosceles triangle is the angle formed by the two equal sides.

Front

If the base angles of an isosceles triangle are 40 degrees, what is the vertex angle?

Back

The vertex angle is 100 degrees (180 - 40 - 40).

Front

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

Back

The angles opposite the equal sides are equal.

Front

How do you find the measure of an unknown angle in an isosceles triangle?

Back

Use the fact that the sum of the angles in a triangle is 180 degrees.

Front

If one leg of an isosceles triangle is 10 cm, what is the length of the other leg?

Back

The other leg is also 10 cm, as both legs are equal.