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.

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 to 60 degrees.

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 degrees.

Front

If two angles of a triangle are equal, what can be said about the triangle?

Back

The triangle is isosceles.

Front

In an isosceles triangle, how do you find the measure of the vertex angle if the base angles are known?

Back

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

Front

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

Back

In an equilateral triangle, all sides are equal, and all angles are equal to 60 degrees.

Front

How do you calculate the perimeter of an equilateral triangle?

Back

The perimeter of an equilateral triangle is calculated by multiplying the length of one side by 3: Perimeter = 3 × side length.

Front

If the length of one side of an equilateral triangle is 24, what is its perimeter?

Back

The perimeter is 72 (3 × 24 = 72).

Front

What is the measure of each angle in an equilateral triangle?

Back

Each angle in an equilateral triangle measures 60 degrees.

Front

In an isosceles triangle, if the base angles are 50 degrees, what is the vertex angle?

Back

The vertex angle is 80 degrees (180 - 2 × 50 = 80).