Problem
GEO-B2-M02-P002 Length of a Tangent
#2
★★☆☆☆ Level 2 of 5
From point \(P\), tangent \(PT\) to a circle and secant \(PAB\) are drawn, where \(A\) is the nearer point. If \(PA=3\), \(PB=27\), find \(PT\).
Use \(PT^2=PA\cdot PB\).
We have \(PT^2=3\cdot27=81\). Therefore \(PT=9\).
A warm-up on the tangent-secant formula.