Complementary & Supplementary Angles

Complementary & Supplementary Angles

By Deena Pardon

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Fill in the Blanks

Complementary Angles are 2 angles that add up to exactly 90°

What is the measurement of ∠KIJ?

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What is the measurement of ∠KIJ?

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∠HIJ is a right angle so we know it is 90°

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What is the measurement of ∠KIJ?

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To find ∠KIJ, we subtract 90° - 65° (whole - part known ​= missing part)

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​90° - 65° = 25°

What is the measurement of ∠MHR?

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What is the measurement of ∠MHR?

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∠MHZ is a right angle so we know it is 90°

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What is the measurement of ∠MHR?

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To find ∠MHR, we subtract 90° - 72° (whole - part known ​= missing part)

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​90° - 72° = 18°

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What is the measurement of ∠FYE and ∠EYW?

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What is the measurement of ∠FYE and ∠EYW?

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​This is a special problem!

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Think about what you DO know about an angle in this picture!​

What is the measurement of ∠FYE and ∠EYW?

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​∠FYW is a right angle so we know it is 90°

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Ray YE splits the angle evenly so...​

What is the measurement of ∠FYE and ∠EYW?

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90° ÷ 2 = 45°

Supplementary Angles are 2 angles that add up to exactly 180°

What is the measurement of ∠MOP?

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What is the measurement of ∠MOP?

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∠NOP is a straight angle so we know it is 180°​

What is the measurement of ∠MOP?

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To find ∠MOP, we subtract 180° - 130° (whole - part known ​= missing part)

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​180° - 130° = 50°

What is the measurement of ∠QSR?

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What is the measurement of ∠QSR?

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∠RST is a straight angle so we know it is 180°

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What is the measurement of ∠QSR?

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To find ∠QSR, we subtract 180° - 114° (whole - part known ​= missing part)

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​180° - 114° = 66°

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What is the measurement of ∠LMN and ∠KMN?

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What is the measurement of ∠LMN and ∠KMN?

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​This is a special problem!

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Think about what you DO know about an angle in this picture!​

What is the measurement of ∠LMN and ∠KMN?

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​∠LMN is a straight angle so we know it is 180°

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Ray MK splits the angle evenly so...​

What is the measurement of ∠LMN and ∠KMN?

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180° ÷ 2 = 90°

A little more practice...

Multiple Choice

What is the definition of a complementary angle?

• Two angles that have the same measure

• Two angles that measure 90 degrees

• A straight line that equals 180 degrees

• Two angles that measure 180 degrees

Multiple Choice

What is the definition of a supplementary angle?

• Two angles that measure 180 degrees

• Two angles that measure 90 degrees

• A right angle

• Two angles that have the same measure

Multiple Choice

Find the missing angle.

• 45°

• 140°

• 50°

• 120°

Multiple Choice

Find the missing angle.

• 28°

• 62°

• 118°

• 180°

Multiple Choice

An angle measures 14°. What is the measure of the complementary angle?

• 76°

• 14°

• 116°

• 68°

Multiple Choice

Find the missing angle.

• 41°

• 51°

• 131°

• 31°

Multiple Choice

What kind of angles are shown?

• Complementary

• Supplementary

• Neither

Multiple Choice

What is an example of a pair of complementary angles?

• 45° and 48°

• 79° and 30°

• 150° and 30°

• 36° and 54°

Multiple Choice

Find the missing angle.

• 76°

• 156°

• 166°

• 86°

Multiple Choice

Find the value of X.

• 15°

• 30°

• 45°

• 90°

Multiple Choice

What kind of angles are shown?

• Complementary

• Supplementary

• Neither