Angle Relationships

Front

What are supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180 degrees.

Front

If ∠A and ∠B are supplementary and ∠A = 120°, what is ∠B?

Back

∠B = 60°

Front

What is the equation to find the missing angle A if ∠A + 43° = 135°?

Back

Front

What are complementary angles?

Back

Complementary angles are two angles whose measures add up to 90 degrees.

Front

If ∠C and ∠D are complementary and ∠C = 30°, what is ∠D?

Back

∠D = 60°.

Front

What are vertical angles?

Back

Vertical angles are the angles opposite each other when two lines intersect. They are always equal.

Front

Name a pair of vertical angles in the figure: ∠1 and ∠4, ∠2 and ∠3.

Back

∠1 and ∠4 are vertical angles.

Front

What is the sum of the measures of angles in a triangle?

Back

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

Front

If one angle in a triangle is 90°, what type of triangle is it?

Back

It is a right triangle.

Front

What is the relationship between angles formed by parallel lines and a transversal?

Back

When a transversal crosses parallel lines, corresponding angles are equal, and alternate interior angles are equal.