Isosceles & Equilateral Triangles

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length. The angles opposite these sides are also 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 property of angles in an isosceles triangle?

Back

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

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 sum of the interior angles of any triangle?

Back

The sum of the interior angles of any triangle is always 180 degrees.

Front

How do you find the measure of the third angle in a triangle if two angles are known?

Back

To find the measure of the third angle, subtract the sum of the two known angles from 180 degrees.

Front

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

Back

In an equilateral triangle, each angle measures 60 degrees.

Front

What is the relationship between the sides of an equilateral triangle?

Back

All sides of an equilateral triangle are equal in length.

Front

If one angle of an isosceles triangle measures 40 degrees, what are the measures of the other two angles?

Back

The other two angles each measure 70 degrees, since the sum of the angles must equal 180 degrees.

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.