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If in a DeltaABC , cos A + 2 cosB+cosC= ...

If in a `DeltaABC` , `cos A + 2 cosB+cosC= 2`, then a,b, c are in

A

A.P.

B

H.P.

C

G.P

D

none of these

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A
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OBJECTIVE RD SHARMA-PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM-Exercise
  1. If in a triangle ABC, b + c = 3a, then tan(B/2)tan(C/2) is equal to

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  2. Let ABC be a triangle such that angle A =45^(@) , angle B =75^(@), the...

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  3. If in a DeltaABC , cos A + 2 cosB+cosC= 2, then a,b, c are in

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  4. If the altitudes of a triangle are in A.P,then the sides of the triang...

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  5. In any !ABC ,the distance of the orthocentre from the vertices A, B,C ...

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  6. If R is the radius of circumscribing circle of a regular polygon of n-...

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  7. If r is the radius of inscribed circle of a regular polygon of n-sides...

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  8. The area of a regular polygon of n sides is (where r is inradius, R is...

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  9. If r,r(1) ,r(2), r(3) have their usual meanings , the value of 1/(r(1)...

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  10. If p(1), p (2), p(3) are respectively the perpendicular from the verti...

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  11. If p(1), p(2),p(3) are respectively the perpendiculars from the vertic...

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  12. If in Delta ABC, 8R^(2) = a^(2) + b^(2) + c^(2), then the triangle ABC...

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  13. If A(1),A(2),A(3) denote respectively the areas of an inscribed polygo...

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  14. If the angles of a triangle are in A.P.with common difference equal 1/...

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  15. In a triangle ABC, A = 8, b = 10 and c = 12. What is the angle C equal...

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  16. If the sides a, b, c of a triangle ABC are the roots of the equation x...

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  17. The area of a !ABC is b^(2)-(c-a)^(2). Then ,tan B =

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  18. In a DeltaABC, Sin A /SinC = sin(A-B)/ sin(B - C) , then a^2, b^2, c^2...

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  19. If in a triangle ABC, 3 sin A = 6 sin B=2sqrt3sin C, then the angle A...

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  20. The side of a Delta are in AP. And its area is 3/5xx (area of an equil...

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