Area: Measure the Space Inside

Could two shapes have the same distance around their edges, but cover different amounts of space? Yes! The secret is to stop looking only at the boundary... and look INSIDE. Area tells you how many square units fit across a flat shape. Watch this rectangle fill with neat, one-centimetre squares, with no gaps and no overlaps.

For a rectangle, you do not need to count every square. Count how many squares fit along the length, then how many rows fit across the width. Multiply length by width. Here, six squares along and four rows make six times four. That is twenty-four square centimetres. Notice the label: centimetres SQUARED, because area counts squares. An L-shape looks trickier, but you can split it into rectangles. Draw a clean line through the inside corner. Find each smaller area separately, then add those areas together. Only count each part once. Do not add all the outside edges unless the question asks for perimeter. Perimeter measures the boundary. Area measures the space inside. Check the task word before choosing your operation.

Let's work through an example. A rectilinear garden is shaped like an L. Its outer rectangle is ten metres long and seven metres wide. A rectangular corner, four metres long and three metres wide, is missing. What is the area of the garden? First, find the whole outer rectangle. Ten times seven equals seventy, so the large rectangle covers seventy square metres. Now highlight the missing corner. Four times three equals twelve, so that cut-out covers twelve square metres. The garden is what remains, so subtract the missing area. Seventy minus twelve equals fifty-eight. The garden's area is fifty-eight square metres. Trace the L-shape once more... every covered square belongs to the answer.

Remember: for a rectangle, multiply length by width. For a rectilinear shape, split it or subtract a missing rectangle, then combine carefully. Keep perimeter on the edge and area INSIDE. Check your units, picture the squares, and answer with confidence. You can do this!