Help, calculate the length of each of the triangles

Antonio made a scale model of a building. the model's scale is 1 inch to 235 feet and its height is 3.5 inches. what is the exact height of the actual building? enter your answer in the box.

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'