Finding Missing Angles in Triangles

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.

Front

If two angles of a triangle are known, how can you find the third angle?

Back

You can find the third angle by subtracting the sum of the known angles from 180 degrees.

Front

What is the formula to find the measure of an unknown angle in a triangle?

Back

The formula is: Unknown Angle = 180 - (Angle 1 + Angle 2).

Front

What is the relationship between the angles in a right triangle?

Back

In a right triangle, one angle is 90 degrees, and the sum of the other two angles is 90 degrees.

Front

How do you denote an unknown angle in algebraic expressions?

Back

An unknown angle is often denoted by a variable, such as x.

Front

What is the definition of an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is the definition of an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees.

Front

What is the definition of a right angle?

Back

A right angle is an angle that measures exactly 90 degrees.

Front

How can you determine if a triangle is valid based on its angles?

Back

A triangle is valid if the sum of its angles equals 180 degrees.

Front

What is the exterior angle theorem?

Back

The exterior angle theorem states that the measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.