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 sides opposite those angles?

Back

The sides opposite the equal angles are also equal in length.

Front

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

Back

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

Front

How do you find the measure of an unknown angle in a triangle?

Back

To find an unknown angle, subtract the sum of the known angles from 180°.

Front

What is the base of an isosceles triangle?

Back

The base of an isosceles triangle is the side that is not equal in length to the other two sides.

Front

What is the vertex angle in an isosceles triangle?

Back

The vertex angle is the angle formed by the two equal sides of the isosceles triangle.

Front

If the lengths of the two equal sides of an isosceles triangle are 10 cm, what is the minimum length of the base?

Back

The minimum length of the base must be greater than 0 cm and less than 20 cm (the sum of the lengths of the two equal sides).

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.