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If a,b and A are given in a triangle and `C_(1), C_(2)` are the possible values of the third side, prove that : `C_(1)^(2)+C_(2)^(2)-2C_(1) C_(2) cos 2A=4a^(2)cos ^(2)A`

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ARIHANT MATHS-PROPERTIES AND SOLUTION OF TRIANGLES -Exercise (Single Integer Answer Type Questions)
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  2. If in A B C ,A=pi/7,B=(2pi)/7,C=(4pi)/7 then a^2+b^2+c^2 must be (a)R...

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

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  4. The orthocenter of the triangle formed by (0,0),(5,−1) and (−2,3) is

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  5. With usual notation in Delta ABC, the numerical value of ((a+b+c)/(r...

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  6. ABC is a triangle and D is the middle point of BC. If AD is perpendicu...

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  7. The rational number which equals the number 2. 357 with recurring de...

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  8. In triangle ABC, r=(R )/(6) and r(1)=7r. Then the measure of angle A =

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  9. In a DeltaABC, the maximum value of 120((sum a cos ^(2)((A)/(2)))/(a+...

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  10. The sides of a triangle are three consecutive natural numbers and its ...

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  11. In DeltaABC, angle C = 2 angle A, and AC = 2BC, then the value of (a^(...

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  12. If a,b and A are given in a triangle and C(1), C(2) are the possible v...

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  13. In Delta ABC, a=5, b=4, c=3. G is the centroid of triangle. If R(1) ...

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  14. A triangle A B C is inscribed in a circle with centre at O , The lines...

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  15. In a triangle ABC, a ge b ge c. If (a^(3)+b^(3)+c^(3))/(sin ^(3)A +s...

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  16. In a cyclic quadrilateral PQRS, PQ= 2 units, QR= 5 units, RS=3 units ...

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