Surface Areas and Volumes

This chapter extends familiar mensuration formulas to combined solids such as hemispheres on cylinders, cones joined to cylinders and similar compound shapes.

Students must identify which faces are exposed and which are hidden or joined. Total surface area should include only the external visible surfaces in the final shape.

The volume of a compound solid is usually the sum or difference of the volumes of simpler solids. Correct unit handling is essential, especially when converting litres, cubic centimetres and cubic metres.

The goal is to model real 3D objects as combinations of standard solids and apply mensuration formulas with care.