Unknown Angles Review

Front

What are unknown angles?

Back

Unknown angles are angles whose measures are not given or are to be determined through calculations or relationships with other angles.

Front

What is the sum of angles in a triangle?

Back

The sum of the interior angles in a triangle is always 180 degrees.

Front

What are corresponding angles?

Back

Corresponding angles are pairs of angles that are in similar positions at each intersection where a straight line crosses two others.

Front

If m∠A = 115°, what is the measure of its corresponding angle?

Back

The measure of the corresponding angle is also 115°.

Front

What is the relationship between vertical angles?

Back

Vertical angles are equal; when two lines intersect, the opposite angles formed are congruent.

Front

How do you find the measure of a missing angle?

Back

To find a missing angle, use the known angles and the properties of angles (like the sum of angles in a triangle or linear pairs) to set up an equation.

Front

What is a linear pair of angles?

Back

A linear pair of angles are two adjacent angles that form a straight line, and their measures add up to 180 degrees.

Front

If m∠1 + m∠2 = 180°, what can be said about ∠1 and ∠2?

Back

Angles ∠1 and ∠2 are supplementary angles.

Front

What is the value of x if m∠A + m∠B + m∠C = 180° and m∠A = 50°, m∠B = x, m∠C = 80°?

Back

x = 50°.

Front

What is the measure of an angle if it is complementary to a 30° angle?

Back

The measure of the angle is 60° because complementary angles add up to 90°.