ABSTRACT
Volume of cuboid = l× b×h and
lb)
A cube is a square prism. If all the sides of a cube are x then
Volume= x3 and surface area = 6x2
Problem 1. A cuboid has dimensions of 12cm by 4cm by 3cm. Determine (a) its volume and (b) its total surface area
The cuboid is similar to that in Figure 27.1, with l = 12cm,b = 4cm and h = 3cm. (a) Volume of cuboid= l × b× h = 12× 4× 3
= 144 cm3
(b) Surface area = 2(bh + hl + lb) = 2(4 × 3+ 3× 12+ 12× 4) = 2(12+ 36+ 48) = 2× 96 = 192 cm2
Problem 2. An oil tank is the shape of a cube, each edge being of length 1.5m. Determine (a) the maximum capacity of the tank in m3 and litres and (b) its total surface area ignoring input and output orifices
(a) of cube 1.5m× 1.5m = 1.53m3 = 3.375m3
1m3 = 100cm× 100cm× 100cm= 106 cm3. Hence,
volume of tank = 3.375× 106cm3
1 litre= 1000cm3, hence oil tank capacity
= 3.375× 10 6
1000 litres = 3375 litres
(b) Surface area of one side = 1.5m× 1.5m = 2.25m2.
