9.1 Introduction and key concepts (EMG5Q)

Knowing how to calculate the perimeter and area of an object can be useful in many contexts, particularly when we need to know how much of a material we require to do a certain task and how much it's going to cost. Some examples of this are calculating the area of a wall, to ensure we buy the correct quantity of paint, or calculating the perimeter of a vegetable garden, so we know how much fencing we need to order.

In this chapter we will learn how to:

• find the perimeter and area of rectangles, squares, triangles and circles by direct measurement and estimation.
• accurately calculate perimeter and area of rectangles, squares, triangles and circles using formulae.
• solve real-life problems and tasks relating to perimeter, area and cost.

Formulae

The plural of formula. One formula, many formulae.