Author note — to cover

Set up equations from angle sums in triangles and on straight lines, equal sides of named shapes, and perimeters and areas with algebraic lengths; solve, then give the angle or length asked for, not the x. The angle facts and mensuration formulae themselves live on the Geometry strand. Both tiers. (A21)

Introduction

—coming soon—

Practice and continue

Practice

Equations from angles and perimeters

Using angle sums, perimeters and areas to set up an equation.

Next lesson

Problems that lead to a quadratic

Area and consecutive-number problems that produce a quadratic.