A trapezoidal pyramid has a volume of 3168 cm3, and its
height is 36 cm. The lengths of the two bases of the
trapezoidal base are 20 cm and 28 cm. What is the height
of the trapezoidal base?

Question

A trapezoidal pyramid has a volume of 3168 cm3, and its 
height is 36 cm. The lengths of the two bases of the 
trapezoidal base are 20 cm and 28 cm. What is the height 
of the trapezoidal base?

anonymous · Answer

Area of a pyramid is 1/3 * Area of the base * Height

The base is a trapezoid... the formula for the area of this is
1/2 * h * (b1 + b2)
1/2 * h * (20 + 28)
1/2 * h * 48
24h

Area of a pyramid is 1/3 * 24h * 36
Area = 288h
3168 = 288h
h = 11 cm

anonymous · Answer

thank you