Isosceles and Equilateral triangles practice

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length.

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 60°.

Front

If two sides of a triangle are congruent, then the angles opposite those sides are __________.

Back

congruent.

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°.

Front

In an isosceles triangle, if the vertex angle is 40°, what are the measures of the base angles?

Back

The base angles are each 70°.

Front

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

Back

Each angle in an equilateral triangle measures 60°.

Front

If one angle of an isosceles triangle is 80°, what is the measure of the other two angles?

Back

Each of the other two angles measures 50°.

Front

How do you find the height of an isosceles triangle?

Back

The height can be found by drawing a perpendicular line from the vertex angle to the base, creating two right triangles.

Front

What is the relationship between the sides and angles in a triangle?

Back

In a triangle, the larger the angle, the longer the opposite side.

Front

If the sides of an equilateral triangle are 6 cm, what is the perimeter?

Back

The perimeter is 18 cm.