Area of a Rectangle

Area measures how much surface a shape covers, counted in unit squares. A floor 6 metres long and 4 metres wide holds 4 rows of 6 one-metre squares: 6 × 4 is 24 square metres. The area of a rectangle is its length times its width.

Why multiply? Each row holds as many squares as the length, and there are as many rows as the width, so the product counts every square without drawing them. Because each piece is a square, area comes in square units: square metres, square feet.

For a shape with a piece cut out, find the whole area and subtract the hole. A shed wall 6 metres wide and 3 metres high with a window 2 metres wide and 2 metres high leaves 6 × 3 - 2 × 2, which is 18 - 4, 14 square metres to paint.