the picture in the attached figure
we know that
PT is tangent to the circle, so ∠RPT is a right angle.
RT is the hypotenuse of a right triangle.
RP=RS ---------> is the
radius of the circle
[tex] RP=15cm [/tex]
By the Pythagorean Theorem
[tex] RT^{2} =PT^{2} +RP^{2} \\ RT^{2} =36^{2} +15^{2} \\ RT^{2} =1,521\\ RT=39cm [/tex]
therefore
the answer is
[tex] RT=39 cm [/tex]
