Triangle Basics Review

Front

What is a triangle?

Back

A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry.

Front

What are the types of triangles based on side lengths?

Back

1. Equilateral: All sides are equal. 2. Isosceles: Two sides are equal. 3. Scalene: All sides are different.

Front

What are the types of triangles based on angles?

Back

1. Acute: All angles are less than 90 degrees. 2. Right: One angle is exactly 90 degrees. 3. Obtuse: One angle is greater than 90 degrees.

Front

What is the Triangle Inequality Theorem?

Back

The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

Front

If two angles of a triangle are 45 degrees each, what is the measure of the third angle?

Back

The third angle measures 90 degrees, as the sum of angles in a triangle is 180 degrees.

Front

What is an equilateral triangle?

Back

An equilateral triangle is a triangle in which all three sides are equal in length and all three angles are equal, each measuring 60 degrees.

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length and the angles opposite those sides are equal.

Front

What is a scalene triangle?

Back

A scalene triangle is a triangle in which all three sides are of different lengths and all three angles are different.

Front

What is the formula for the area of a triangle?

Back

Area = 1/2 * base * height.

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 degrees.