Math, asked by srimaninayak7, 9 days ago

please give me correct answer​

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Answers

Answered by AestheticDude
11

Answer :-

  • 165°.

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Question :-

  • The four angles of a pentagon are 40°, 75° , 125° and 135° . The measure of the fifth angle is :-
  1. 165°
  2. 170°
  3. 160°
  4. 175°

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Answer :-

  • The four angles of a pentagon are 40°, 75° , 125° and 135° . The measure of the fifth angle is :-
  1. 165°
  2. 170°
  3. 160°
  4. 175°

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Given :-

  • Four angles of a pentagon (Five sided figure) that are 40°, 75° , 125° and 135°

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Find :-

  • Fifth angle of the pentagon .

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We know :-

  • Sum of interior angles of pentagon is 540° .

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Solution :-

Let the fifth angle be X .

∴ X + 40° + 75° + 125° + 235° = 540° [Sum of interior angles of pentagon is 540° ].

⟹ X + 375° = 540°

⟹ X = 540° - 375°

⟹ X = 165° .

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Regular Polygon Name Each

interior angle

  • Triangle • 60°
  • Quadrilateral • 90°
  • Pentagon • 108°
  • Hexagon • 120°
  • Septagon • 128 . 57°
  • Octagon • 135°
  • Nonagon • 140°
  • Decagon • 144°

Note :- It is written each interior angle and not all . So, Don't be confused by seeing that pentagon is 540° , then how here it is 108° . It I because in 540° we multiplied 5 with 108° see 108° multiply 5 = 540° .

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How , 540° came :-

We know it is pentagon that means which has 5 sides .

So, let

n be No. of sides then, Using the formula

Sum of all angles of a Polygon

2n-4 90°

Here , n = 5

➨2✖5 -4 ✖ 90°

➨10-4✖90°

➨6✖90°

➨ 540°

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