Volume of Composite Cylinders

A composite solid is built from simpler solids, so its volume is found by adding the parts or taking a hole away. In NSW Year 8 maths (NESA outcome MA4‑VOL‑C‑01) this includes stacked cylinders, a cylinder on a prism and pipes, where \(V = \pi(R^2 - r^2)h\).

You will square each radius before subtracting, find inside sizes from a wall thickness, keep \(\pi\) exact until the last line, and use cross-sections made of a square and a semicircle. You will also find the wood termites ate from a log to make an emu caller, the concrete in a skate ramp, the wood wasted turning a cylinder on a lathe and how many washers a block of steel makes. It is part of Year 8 Volume.