9514 1404 393
Answer:
RQ = 48
Explanation:
The product of secant segment lengths to the points of intersection with the circle is the same for both secants. The tangent is a degenerate case where the two points of intersection are the same.
ST·ST = SR·SQ
SQ = ST^2/SR = 45^2/27 = 75
RQ = SQ -SR = 75 -27
RQ = 48