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 are the properties of an isosceles triangle?

Back

1. Two sides are equal in length. 2. The angles opposite the equal sides are equal.

Front

How do you find the vertex angle of an isosceles triangle?

Back

The vertex angle can be found using the formula: Vertex Angle = 180° - 2(Base Angles).

Front

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

Back

The vertex angle is 100°.

Front

What is the relationship between 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 one leg of an isosceles triangle is 10 cm and the other leg is also 10 cm, what is the minimum length of the base?

Back

The minimum length of the base must be greater than 0 cm.

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 significance of the equal sides in an isosceles triangle?

Back

The equal sides create symmetry, which affects the triangle's properties and angle measures.

Front

How can you determine if a triangle is isosceles?

Back

Measure the lengths of the sides; if at least two sides are equal, it is an isosceles triangle.