Angle Pairs

Vertical Angles

• Two angles formed by intersecting lines and have no sides in common.

• Are congruent.

Vertical Angles

Supplementary Angles

• Two angles sharing one side that add up to exactly 180°

Supplementary Angles

Complementary Angles

• Two angles, sharing one side that add up to exactly 90°

Complementary Angles

Adjacent Angles

• Adjacent angles share a common vertex and one common side.

Adjacent Angles

Adjacent Angles

Supplementary vs. ComplementaryHow do I remember?

• The way I remember is this:

• C comes before S in the alphabet.

• 90 comes before 180 when I count.

• Complementary is 90, Supplementary is 180.

Guess Who?

• I am an angle.

Guess Who?

• I am an angle.

• I have 180°

Guess Who?

• I am an angle.

• I have 180°

• I look like this:

Guess Who?

• I am an angle.

• I have 180°

• I look like this:

Supplementary Complementary

Guess Who?

• I am two adjacent angles.

Guess Who?

• I am two adjacent angles.

• I look like an “L” with a line in the middle.

Guess Who?

• I am two adjacent angles.

• I look like an “L” with a line in the middle.

• I add up to 90°

• I look like this:

Guess Who?

• I am two adjacent angles.

• I look like an “L” with a line in the middle.

• I add up to 90°

• I look like this:

Complementary Supplementary

Guess Who?

Complementary Supplementary

Guess Who?

Complementary Supplementary

Review

• Complementary angles are…….

Review

• Complementary angles are…….

Review

• Supplementary Angles are…..

Supplementary Angles

Vertical Angles are…….

Vertical Angles

Adjacent Angles are…

Adjacent Angles

Find the missing angle

55

x

I know that these angles are complementary.

They must add up to 90°

So……

90 – 55 = 35

The missing angle is 35

You try.

20x

Are they supplementary or complementary?

Find the missing side.

You try.

20x

Are they supplementary or complementary?

complementary

Find the missing side.

90 – 20 = 70

The missing angle

Is 70

One More

50

x

Find the missing angle

120x

I know these are supplementary angles.

Supplementary angles add up to 180.

The given angle is 120. So…..

180 – 120 = 60

The missing angle is 60

Find the missing angle

130x

What kind of angles?

What’s the missing angle?

Find the missing angle

130x

What kind of angles?

Supplementary

What’s the missing angle?

Adds up to 180, so…..

180 – 130 = 50

Find the missing angle

x30

Do this one on your own.

Right

Wrong