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MHT CET202019 Oct 2020Evening ShiftMathematicsProperties of TrianglesActual

The area of the triangle ABC is 10 3 ~cm ² , angle B is 60^ and its perimeter is 20 ~cm , then ( AC )=

Options

  1. A7 ~cm
  2. B8 ~cm
  3. C10 ~cm
  4. D5 ~cm

Correct answer

A. 7 ~cm

Step-by-step solution

(D) array l Area = acsin B 2 =10 3 = acsin 60 2 10 3 = ac 3 4 a c=40 array Now aligned & B = a ²+ c ²- b ² 2 ac & 60 2 ac = a ²+ c ²- b ² & 1 2 2 40=( a + c )²-2 ac - b ² aligned 40=(20-b)²-(2 40)-b² [a+b+c=20 , given ] aligned &=400+b²-40 b-80-b² 40 b &=280 b=7 aligned

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