Types of Angles

Lines a and b are parallel. They are cut by a transversal. This creates 8 different angles.

Draw this picture on your paper. Be sure to label the angles correctly.

Angles 1,2,7, and 8 are exterior angles,because they are outside the parallel lines.

Angles 3,4,5, and 6 are interior angles, because they are inside the parallel lines.

Corresponding angles – angles that have the same position on two different parallel lines cut by a transversal

Corresponding angles are congruent.

1 and 5 2 and 6 4 and 8 3 and 7

Alternate exterior angles – nonadjacent exterior angles found on opposite sides of the transversal

Alternate exterior angles are congruent.

1 and 7 2 and 8

Alternate interior angles – nonadjacent interior angles found on opposite sides of the transversal

Alternate interior angles are congruent.

4 and 6 3 and 5

Supplementary angles – two angles whose sum is 180

1 and 4 5 and 8 2 and 3 6 and 7

1 and 2 3 and 4 5 and 6 7 and 8

Complimentary angles – angles whose sum is 90

a

b

ma + mb = 90

Vertical angles – two pairs of opposite angles formed by intersecting lines

1 and 3 2 and 4 5 and 7 6 and 8

Vertical angles are congruent.

If 4 = 50, find the measure of each of the other angles. Give a reason for each answer.

x124

Find the value of x.

In the figure, m1 = 80, find the measure of the other 3 angles.

Explain your reasoning.

Find m4 if m2 = 80. Explain your reasoning.

b = 2x + 17

a = 5x – 40

Find the measure of each angle.