Question

two concentric circles are of radii 10cm and 8cm.RP and RQ are tangents to the two circles from R. If the length of RP is 24cm find the length of RQ.................Any1 plzzz answr dis ques fast

Answer 1

Let the circles have common centre O. Let RP and RQ be the tangents to the larger and smaller circle respectively. Join OP, OQ, OR. By Pythagoras Theorem, OR2 =OP2+PR2 , OR2=102+242, OR2=100+576=676, OR=26. In the right triangle OQR, RQ2=OR2-OQ2=262-82=676-64=612. RQ=sq.root 612 = 6 root 17. This is the Answer for the above question.

Answer 2

Let RP=tangent to bigger circle=24cm

And

RQ=Tangent to smaller circle.

At the point where the radius of the bigger circle meets the tangent,, a right angled triangle is formed.

The length PQ=10cm-8cm =2cm

We get triangle RPQ which is a right angled triangle.

We therefore use pythogras theorem to get the required length RQ which is the tangent of the smaller circle.

(24×24) + (2×2)=580cm2

Getting the square root of 580cm2

We get:24.0831cm

QR=24.0831CM

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