Isosceles and Equilateral Triangles

Front

What is an isosceles triangle?

Back

A triangle with at least two sides of equal length.

Front

What is an equilateral triangle?

Back

A triangle with all three sides of equal length and all three angles equal to 60°.

Front

What are the properties of an isosceles triangle?

Back

The angles opposite the equal sides are also equal.

Front

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

Back

180°.

Front

How do you find the missing angle in a triangle?

Back

Subtract the sum of the known angles from 180°.

Front

What is a right triangle?

Back

A triangle that has one angle measuring 90°.

Front

What is an acute triangle?

Back

A triangle where all three angles are less than 90°.

Front

What is an obtuse triangle?

Back

A triangle that has one angle measuring more than 90°.

Front

What is the Pythagorean theorem?

Back

In a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.

Front

What is the definition of complementary angles?

Back

Two angles that add up to 90°.