In the given figure, two circles touch each other at a point CCC. Prove that the common tangent to the circles at CCC bisects the common tangent at the points PPP and QQQ.
Answer:
- We see that PRPRPR and CRCRCR are the tangents drawn from an external point RRR on the circle with center AAA.
Thus, PR=CR …(i)PR=CR …(i)PR=CR …(i)
Also, QRQRQR and CRCRCR are the tangents drawn from an external point RRR on the circle with center BBB.
Thus, QR=CR …(ii)QR=CR …(ii)QR=CR …(ii) - From eq (i)eq (i)eq (i) and eq (ii)eq (ii)eq (ii), we get
PR=QR [Both are equal to CR]PR=QR [Both are equal to CR]PR=QR [Both are equal to CR]
Therefore, RRR is the midpoint of PQPQPQ. - Thus, we can say that the common tangent to the circles at CCC bisects the common tangent at the points PPP and QQQ.