What is pt?

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Answer 1 · 2018-03-30T03:57:28

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Given that PT is a tangent and PA is secant of a circle.

And #PB=4cm and BA=9cm#

We are to find out PT

Construction #T,B and A,T# are joined

#Delta BPT and DeltaAPT# are similar

Since

#angle BPT=angleAPT# common.

#angle BTP="alternate "angle PAT#

So

#(PT)/(AB)=(BP)/(PT)#

#=>PT^2=ABxxBP=9xx4#

#=>PT=6# cm