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The angles A, B and C of a triangle are ...

The angles A, B and C of a triangle are in A.P. If AB= 6 units, BC = 7units, then AC is equal to

A

5 units

B

7 units

C

8 units

D

none of these

Text Solution

Verified by Experts

It is given that A, B and C are in A.P.
`therefore2B=A+C`
`rArr3B=A+B+C`
`rArr3B=pi` `[because A+B+C=pi]`
`rArrB=pi/3`
`rArrcosB=1/2`
`rArr(a^(2)+c^(2)-b^(2))/(2ac)-1/2rArr49+36-b^(2)=42rArrb=sqrt(43)`
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OBJECTIVE RD SHARMA-PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM-Chapter Test
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  12. If the angles A, B, C (in that order) of triangle ABC are in arithmeti...

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  18. In DeltaABC if a=(b-c)sectheta then (2sqrt(bc))/(b-c)sin(A/2)=

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