here we see the student standing and creating a small triangle that is equivalent to the big triangle since it has the same angles, the only difference is that its smaller, so what we have to do is make a proportion of both triangles, so since 8 ft correspond with the 40 ft they're going to be in the same part of the proportion and the other measurements, including x, on the other part, so itll be 5/8 and x/40, see how the 8 and 40 are both on the bottom? thats because they correspond, so now all you have to do is cross butterfly, so you can set up an expression on 8x= 5*40 or you can just multiply 5*40 and then divide by 8, your answer will be x= 25 ft
