A swimming pool 9 m wide and 12 m long is 1 m deep on the shallow side and 4 m deep on the deeper side. Its volume in m3 is:

Step-by-step explanation:

This cross section of swimming pool can be divided into two geometric shapes :

Rectangle of dimension 12m x 1m

Triangle with base = 12m, altitude = 3m

Area of Rectangular shape = 12m x 1m = 12m²

Area of triangle = 1/2 x 12 x 3 = 18 m²

Total Area of Cross Section = 30 m²

Total Volume = 30m² x 9m = 270m³

d. all of the above

step-by-step explanation: