Area of Kites and Rhombuses

A kite and a rhombus share one area formula, half the product of the diagonals: \(A = \frac{1}{2}xy\). In NSW Year 8 maths (NESA outcome MA4‑ARE‑C‑01) the formula comes from the rectangle drawn around the two diagonals, which the shape fills exactly half of.

You will use only the diagonals and never the sides, double a half-diagonal when that is all the diagram gives, and find a missing diagonal from the area. You will also work on the number plane, count rhombus tiles for a bathroom wall, find the fabric for a kite and a paddock's area in hectares, and take a kite-shaped hole out of a timber panel. It is part of Year 8 Area and Perimeter.