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 where 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

180°.

Front

In an isosceles triangle, what can be said about the angles opposite the equal sides?

Back

They are equal.

Front

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

Back

All angles are equal and measure 60°.

Front

How do you find the height of an isosceles triangle?

Back

Drop a perpendicular from the vertex opposite the base to the midpoint of the base.

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

If two angles of a triangle are 45° each, what type of triangle is it?

Back

It is an isosceles triangle.

Front

What is the definition of complementary angles?

Back

Angles that add up to 90°.

Front

What is the definition of acute angles?

Back

Angles that measure less than 90°.