The b represents the y- intercept in a graph (where the line crosses the y axis). The m represents the slope of the line. You can find the slope by taking the rise of the graph and dividing it by the run (rise/run). If you get the numbers in the equation form y=mx+b, then you just take the information they give you out of the equation.
A^2 + b^2 = c^2 20^2 = 400 52^2 = 2704 400 + b^2 = 2704 2704 - 400 = 2304 So you need the square root of 2304 which is 48 so the length of the other leg is 48 ft.
