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In a Delta ABC, show that (a cos A+b co...

In a `Delta ABC, ` show that `(a cos A+b cos B+ c cos C)/(a+b+c)= (r )/(R )`

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ARIHANT MATHS-PROPERTIES AND SOLUTION OF TRIANGLES -Exercise For Sesssion 3
  1. If 8R^(2)=a^(2) +b^(2) +c^(2). then prove that the Delta is right angl...

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  2. In a Delta ABC, show that 2R^(2) sin A sin B sin C=Delta.

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  3. In a Delta ABC, show that (a cos A+b cos B+ c cos C)/(a+b+c)= (r )/(R...

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  4. If the sides of a triangle are in the ratio 3 : 7 : 8, then find R : r

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  5. In an equilateral triangle show that the in-radius and the circum-radi...

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  6. In any DeltaABC, find sin A+sin B+ sin C.

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  7. In any Delta ABC, show that cos A+ cos B+ cos C = (1+ (r )/(R )).

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  8. Prove that (r(1) -r)/(a) + (r(2) -r)/(b) = (c)/(r(3))

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  9. Prove that r(1) r(2) + r(2) r(3) + r(3) r(1) = (1)/(4) (a + b + c)^(2)

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  10. In triangle ABC .If(r(1)+ r (2))(r (2)+ r (3)) (r(3)+r(1))=4Rs^(2)Then...

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  11. If r(2) +r(3)+ r = r(1), then show that Delta is right angled.

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  12. In an equilateral triangle, the inradius, circumradius, and one of the...

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  13. Show that ((1)/(r (1))+ (1)/(r(2)))((1)/(r(2))+(1)/(r (3)))((1)/(r (3)...

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  14. The ex-radii r(1), r(2), r(3) of a DeltaABC are in Hp, show that its s...

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  15. In a DeltaABC, show that r(1)* r(2)* r(3)*r=Delta^(2).

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  16. If l(1), l(2), l(3) are respectively the perpendicular from the vertic...

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  17. If the angle opf a triangle are in the ratio 1:2:3, then show that the...

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  18. Show that, 4 R r cos ""A/2cos ""B/2 cos ""C/2 =Delta

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  19. If in Delta ABC, (a -b) (s-c) = (b -c) (s-a), prove that r(1), r(2), r...

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  20. In a triangle ABC,if 1/r1^2+1/r2^2+1/r3^2+1/r^2=

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