Isosceles Triangles

Front

What is an isosceles triangle?

Back

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

Front

What is the vertex angle in an isosceles triangle?

Back

The vertex angle is the angle opposite the base of the isosceles triangle.

Front

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

Back

The base angles of an isosceles triangle are equal and can be found using the formula: Base Angle = (180° - Vertex Angle) / 2.

Front

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

Back

Each base angle is 70°.

Front

What is the property of the angles in an isosceles triangle?

Back

The sum of the angles in any triangle is 180°. In an isosceles triangle, the two base angles are equal.

Front

If the lengths of the equal sides of an isosceles triangle are 5 cm, what is the minimum length of the base?

Back

The minimum length of the base must be greater than 0 cm and less than 10 cm (5 + 5 > base > 5 - 5).

Front

What is the formula for the area of an isosceles triangle?

Back

Area = (base * height) / 2.

Front

If the base of an isosceles triangle is 8 cm and the height is 5 cm, what is the area?

Back

Area = (8 * 5) / 2 = 20 cm².

Front

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

Back

In an isosceles triangle, the angles opposite the equal sides are also equal.

Front

How can you determine if a triangle is isosceles using side lengths?

Back

If two sides of a triangle are of equal length, then the triangle is isosceles.