Composite Areas and Problems on Areas

A composite shape is made from simpler shapes, so its area is found by adding the parts or by taking a missing piece away from a larger shape. This NSW Year 8 maths subtopic (NESA outcome MA4‑ARE‑C‑01) combines rectangles, triangles, parallelograms, trapeziums and rhombuses.

You will split shapes along a dashed line, work out missing lengths first, subtract one or more holes, and handle two paths that cross by taking the shared square away once. You will also cost a pebble path around a pool, count the floor tiles for an L-shaped laundry, find the lawn left around a shed slab and work backwards from the cost of turf to a missing length. It is part of Year 8 Area and Perimeter.