# Supplementary Angles

**Supplementary angles : When two angles add up to 180**

^{0}**Example :**

1) 60,120 2) 179, 1 3) 90,90 etc.

**Important Points**

i) Two acute angles can not be supplement of each other.

ii) Two right angles are always supplementary.

iii) Two obtuse angles can not be supplementary of each other.

**Examples :**

1) The two angles are supplementary. If one of the angle is thrice that of the other then find the two angles.

**Solution :**

As we know that sum of two supplementary-angles is 180

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Let one angle be x so other angle be 3x.

x + 3x = 180

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4x = 180

x = 180/4

x = 45

&ther4; one angle = 45

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and other angle = 3x = 3 x 45 = 135

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2) Two supplementary-angles differ by 34

^{0}. Find the angles.

**Solution :**

Let one angle = x

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Other angle = (x + 34)

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As we know that sum of two supplementary-angles is 180

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∴ x + x + 34 = 180

⇒ 2x + 34 = 180

⇒ 2x = 180 – 34

⇒ 2x = 146

⇒ x = 146/2

⇒ x = 73

Other angle = 73 + 34 = 107

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Hence, the measures of two angles are 73

^{0}and 107

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**Practice**

**Q.1 Check whether the following angles are supplementary or not.**

1) 45

^{0}and 130

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2) 30

^{0}and 115

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3) 112.8

^{0}and 67.2

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4) 1

^{0}and 179

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5) 34

^{0}and 150

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**Basic Geometry**

• Point

• Lines

• Angles

• Lines and Angles

• Complementary angles

• Supplementary angles

• Vertically Opposite Angles

• Linear Pair Angles

• Adjacent Angles

• Parallel Lines

• Solved Problems on Intersecting Lines

• Solved Problems on Parallel Lines

• Point

• Lines

• Angles

• Lines and Angles

• Complementary angles

• Supplementary angles

• Vertically Opposite Angles

• Linear Pair Angles

• Adjacent Angles

• Parallel Lines

• Solved Problems on Intersecting Lines

• Solved Problems on Parallel Lines