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°.

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

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 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°.

Front

How do you calculate the measure of an angle in an isosceles triangle if one base angle is given?

Back

Use the formula: Vertex Angle = 180° - 2(Base Angle).

Front

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

Back

The vertex angle is 100°.

Front

What is the formula for the area of a triangle?

Back

Area = 1/2 * base * height.

Front

How do you find the height of an isosceles triangle?

Back

The height can be found using the Pythagorean theorem if the lengths of the sides are known.