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 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 sides opposite those angles?

Back

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

Front

In an isosceles triangle, if the vertex angle measures 40 degrees, what is the measure of each base angle?

Back

Each base angle measures 70 degrees.

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 find the measure of an unknown angle in a triangle?

Back

To find the measure of an unknown angle in a triangle, subtract the sum of the known angles from 180 degrees.

Front

If the lengths of two sides of an isosceles triangle are 10 cm and 10 cm, what is the minimum possible length of the third side?

Back

The minimum possible length of the third side must be greater than 0 cm and less than 20 cm.

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 triangle ABC, if AB = AC and ∠B = 50 degrees, what is the measure of ∠C?

Back

The measure of ∠C is also 50 degrees, making triangle ABC isosceles.