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.
