A rectangular pyramid has a base that measures 8 inches by 10 inches, a height of 12 inches, and a slant height of 15 inches. Elena calculated the volume of the pyramid as shown. V = 1
3
Bh

V = 1
3
(80)(15)

V = 400 in.3

What was her mistake?
Elena used the wrong units.
Elena incorrectly used the slant height instead of the height.
Elena multiplied incorrectly.
Elena should not have multiplied by one third.