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

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 type of triangle is it?

Back

It is an isosceles triangle.

Front

What is the relationship between the base angles and the vertex angle in an isosceles triangle?

Back

The base angles are equal, and the vertex angle can be found by subtracting the sum of the base angles from 180°.

Front

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

Back

If the base angle is known, the vertex angle can be calculated using the formula: Vertex Angle = 180° - 2(Base Angle).

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

In an equilateral triangle, what is the measure of each angle?

Back

In an equilateral triangle, each angle measures 60°.

Front

If the length of one side of an equilateral triangle is 10, what is the perimeter?

Back

The perimeter of an equilateral triangle is 3 times the length of one side, so the perimeter is 30.

Front

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

Back

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