In the diagram below, secants RST and RQP drawn from point R, intersect circle O at S, T, Q, and P. If RS = 6, ST = 4, and RP = 15, what is the length of RQ?
Secant-Secant Theorem
We have the following relationship
RS ( RS + ST) = RQ ( RP)
6 ( 6 + 4) = RQ (15)
6 (10) = RQ (15)
60 = RQ (15)
60 / 15 = RQ = 4
