Equilateral and Isosceles Triangle

Front

What is an equilateral triangle?

Back

A triangle where all three sides are of equal length and all three angles measure 60 degrees.

Front

What is an isosceles triangle?

Back

A triangle with at least two sides of equal length and the angles opposite those sides are equal.

Front

What is the sum of the interior angles of a triangle?

Back

180 degrees.

Front

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

Back

Subtract the sum of the known angles from 180 degrees.

Front

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

Back

The angles opposite the equal sides are equal.

Front

What is the measure of each angle in an equilateral triangle?

Back

60 degrees.

Front

If two sides of a triangle are equal, what can be said about the angles opposite those sides?

Back

They are equal.

Front

What is the definition of congruent sides?

Back

Sides that are of equal length.

Front

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

Back

70 degrees each.

Front

What is the formula for the area of a triangle?

Back

Area = 1/2 * base * height.