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If in a DeltaABC, (a cos A+b cos B+ c co...

If in a `DeltaABC, (a cos A+b cos B+ c cos C)/(a sin B+b sin C+ c sin A)=(a+b+c)/(9R)`, then prove that `Delta` is equilateral.

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ARIHANT MATHS-PROPERTIES AND SOLUTION OF TRIANGLES -PROPERTIES AND SOLUTIONS OF TRIANGLES EXERCISE 7 : SUBJECTIVE TYPE QUESTIONS
  1. A hexagon is inscribed in a circle of radius r. Two of its sides have ...

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  2. Prove that a^(2)+ b^(2) +c^(2) +2abclt2, where a,b,c are the sides of ...

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  3. Find the radian measure corresponding to the following degree measure ...

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  4. A polygon of n sides, inscribed in a circle, is such that its sides su...

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  5. Find the radian measure corresponding to the following degree measure ...

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  6. Find the value of the trigonometric function sin((5pi)/6)

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  7. Find the radian measure of the following degree measure 75°

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  8. If in a DeltaABC, (a cos A+b cos B+ c cos C)/(a sin B+b sin C+ c sin A...

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  9. In Delta ABC, 'h' is the length of altitude drawn from vertex A on th...

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  10. Find the value of other five trigonometric functions if cosx = -3/5 , ...

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  11. If in a Δ A B C , b = √ 3 , c = 1 and B − C = 90 ∘ , then ∠ A is

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  12. An equilateral triangle PQR is circumscribed about a given DeltaABC. P...

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  13. Find the other five trigonometric functions if cosx = 4/5 , x lies in ...

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  14. Find the points inside a Delta from which the sum of the squares of di...

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  15. In triangle ABC, line joining the circumcenter and orthocentre is para...

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  16. Find the value of trigonometric function cot((-15pi)/4)

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  17. Prove that sin^2(30°) + cos^2(60°) - tan^2(45°) = -1/2

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  18. Prove that (2cos^3x-cosx)/(sinx - 2sin^3x) = cotx

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