You would multiply by

.
When you rationalize the denominator, you multiply by the conjugate of the denominator. The conjugate is the same numbers and radicals, but with the sign of the radical switched.
Answer:
16.06
20characterlimitlmasdfdgfds
Since these are similar triangles you can use any two corresponding sides to figure out the scale factor.
Use the bottom side. Going from the first triangle to the second the scale factor is:
15/9 = 5/3
1.5= 1 lap+ 0.5 lap = [2(85)+pi*(d)] + [85+pi*d/2]= 3[(85)+pi*d(1/2)]
just substitute d=74