The volume of the Canada Post mail box
= Volume of the Cuboid + Volume of the Triangular Prism
= ( L X B X H ) + Area of the base x Height
= ( 85 x 70 x 180 ) + ( 1/2 x 70 x 25 ) x 85
= 1,071, 000 + ( 875 x 85)
= 1,071, 000 + 74,375
= 1, 145,375 cm^3
