Composite Shapes for Volume

A composite solid is still a prism when the same face runs all the way through. In NSW Year 8 maths (NESA outcome MA4‑VOL‑C‑01) the work goes into the area of that cross-section, built by adding simple shapes or taking a hole away, before using \(V = Ah\).

You will find missing lengths first, split L-shapes, plus signs and I-beams into rectangles, add a triangle or trapezium for a roof or a ramp, and use Pythagoras' theorem for a sloping height. You will also find the concrete in a culvert or a hollow building block, the litres in a pond with a shelf, and how many bags of soil fill a garden bed. It is part of Year 8 Volume.