You can just multiply the top and the bottom by the same number, and you will get equivalent fractions.
Using equation of motion.
S = ut + (1/2)gt²
Where S = Height, t = time, g = acceleration due to gravity = 9.8 m/s²
time, t = 8 seconds
Since it was dropped from height, initial velocity, u = 0
S = 0*t + (1/2)gt²
S = (1/2)gt²
S = (1/2)*9.8*8² = 4.9 * 8 * 8 = 313.6
Therefore the ledge is 313.6 m tall.
Let s be the side length of the square. The dimensions of the rectangle are three times the side of the square (i.e. 3s), and two less than the side of the square (i.e. s-2).
So, the area of this rectangle is

The area of the square is
, and we know that the two areas are the same, so we have

The solution s=0 would lead to the extreme case where the rectangle and the square are actually a point, so we accept the solution s=3.