Algebra
posted by Jessie .
Volume of a triangular prism:1000 cu ft
Length of base: ??
Height of base: 2ft
Height of prism:40ft

Volume = (1/2) b h L = L*(base area)
If 40 ft is the LENGTH L of the prism, the base area is 1000/40 = 25 ft^2.
Then, since (1/2) b*h = 25
base length b = 25*2/h = 25 ft
(if h = 2 is the base height)