InterviewSolution
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InterviewSolution
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In `DeltaABC`, if `sin A + sin B + sin C= 1 + sqrt2 and cos A+cos B+cosC =sqrt2` then the triangle isA. equilateralB. isoscelesC. right angledD. right angle isosceles |
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Answer» Correct Answer - D If the triangle is equilateral `sin A+ sin B+sin C=(3sqrt(3))/(2)` If the triangle isosceles, let `A=30^(@),B=30^(@), C=120^(@)`. Then, `sin A+ sin B+ sin C=1+(sqrt(3))/(2)` If the triangle is right angled, let `A=90^(@), B=30^(@),C=60^(@)`. Then `sin A+ sin B + sin C=(3+sqrt(3))/(2)` If the triangle is right angled isoceles, then one of the angles is `90^(@)` and the remaining two are `45^(@)` each, so that `sin A+ sin B + sin C = 1+sqrt(2)` and `cos A + cos B + cos C = sqrt(2)` |
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