Volume of Square Based Pyramid = (1/3)*(Side Length of Base)^2 *(height)
the given information are:
Volume = 120
height = 10
plug this in and get:
120 = (1/3)*(side)^2 *(10)
12 = (1/3)*(side)^2 [divided both sides by 10]
36 = (side)^2 [multiplied both sides by 3]
(side) = 6 [square rooted both sides]
Therefore the Side Length of the Base is 6 meters.