9/100 = x/90
Cross multiply to get 810 = 100x
Divide both sides by 100 to get x = 81 inches
SSS or Side Side Side Theorem.
We have congruent triangles when corresponding sides are congruent; we call it a theorem but that's pretty much the definition of congruent triangles.
I think the answer is 32% because if you turn 32% into a decimal (which would be 0.32) then multiply it by 25 you would get 8. Which then means if he stopped 8 times and went through 25 intersections then he stopped at 32% of the intersections. I hope this helps :)