Today we will look at some angle relationships!

•Vertical Angles

•Adjacent Angles

•Complementary Angles

•Supplementary Angles

It takes two to tango!

Special Angle Pairs:

1) Vertical Angles – the angles

formed on opposite sides of

intersecting lines.

12

43

<2 and <4 are vertical angles so we know

m<2 = m<4

Vertical angles are always congruent

2) Adjacent Angles – are angles that share a common vertex and a common side.

21

1

2

12

Complementary Angles – two angles whose sum is 90 degrees

Supplementary Angles – two angles whose sum is 180 degrees

Complementary Angles

60

X

90 - 60 = X

30 = X

What is the complement of a 72 degree angle?

What is the complement of a 35 degree angle?

18 degrees

55 degrees

Supplementary Angles

38 X

X = 180-38 X = 142 degrees

360°

180°