Isosceles and Equilateral Triangles

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length and the angles opposite those sides are equal.

Front

What is an equilateral triangle?

Back

An equilateral triangle is a triangle in which all three sides are of equal length and all three angles are equal, each measuring 60°.

Front

How do you find the vertex angle of an isosceles triangle if the base angles are known?

Back

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

Front

If an isosceles triangle has a base angle of 40°, what is the vertex angle?

Back

The vertex angle is 100°.

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is always 180°.

Front

In an isosceles triangle, if the two equal sides are 10 cm each, what is the minimum possible length of the base?

Back

The minimum possible length of the base is greater than 0 cm but less than 20 cm.

Front

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

Back

In an equilateral triangle, all angles are equal and each measures 60°.

Front

How do you determine if a triangle is isosceles?

Back

A triangle is isosceles if at least two of its sides are of equal length.

Front

What is the formula for the area of a triangle?

Back

The area of a triangle can be calculated using the formula: Area = 1/2 * base * height.

Front

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

Back

The area is 20 cm².