Topic 11: Nets, Areas and Volumes of Solids – Sample Activity

Context

Nets, Areas and Volumes of Solids Vivo energy has a fuel tank reservoir whose capacity is 30,000m3. The tank requires painting because its colour has faded due to the effects of weather. The tank is cylindrical in shape and its height is 10% larger than its diameter. The manager in charge of maintenance wishes to have its outer surface (top and curved surface) painted. She contacts a certain Ugandan paint-producing company to purchase the tins of paint required.

Support Material

Every 5-litre tin of paint costs UGX 40,000 and can paint 60 m2 of surface.

Task

As a sales agent of the paint company, advise the maintenance manager on the cost of paint needed for the repair of the reservoir tank.

Topic Summary

In this topic, you have learnt that: most solid containers like boxes used for parking originate from nets a solid may have more than one net. For example, the two nets above may all be folded to form a cuboid. for any given solid with clear edges, number of faces = number of vertices. the units of a calculated value are obtained from units of the individual quantities used to obtain the result. the total surface area of a three-dimensional figure is the sum of the individual surfaces of the figure. the volume of a uniform three-dimensional figure, e.g. a square and rectangle, is obtained from: Volume = base area x height.