TYPES OF ANGLESSupplementary and Complementary Angles

What are Supplementary Angles?

Two Angles are Supplementary if they add up to 180 degrees.

Example

These two angles (140° and 40°) are Supplementary Angles, because they add up to 180°.

NOTE

These two are supplementary because 60° + 120° = 180°

What are Complementary Angles?

Two Angles are Complementary if they add up to 90 degrees (Right Angle).

Example

These two angles (40° and 50°) are Complementary Angles, because they add up to 90°.

NOTE

These two are complementary because 27° + 63° = 90°

How can you remember which is which? Easy! Think:

"C" of Complementary stands for "Corner" (Right Angle)

"S" of Supplementary stands for "Straight" (180 degrees is a straight line)

ACTIVITY

40

ARE THE TWO ANGLES SUPPLEMENTARY?

140

40

60

60 30

ARE THE TWO ANGLES COMPLEMENTARY?

CAN YOU FIND THE MISSING ANGLE?

180

X

WELL DONE!By: Rochelle Gordon