Finding the Area of a Rectangle Area of

Finding the Area of a Rectangle

Area of a Rectangle Objectives • To calculate areas of rectangles • To calculate areas of polygons made of rectangles

Area of a Rectangle Area is the measure of how much space a shape takes up. We measure it in squares such as square centimeters or meters etc. 1 cm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 This rectangle takes up 28 squares. It has an area of 28 square centimetres 28 cm 2

Area of a Rectangle It could take a long time to cover shapes in squares. Luckily there is an quicker way. 7 cm 4 cm × = 28 cm 2

Area of a Rectangle Use this formulae to find the area of rectangles. length Width Area of a rectangle = length × width

Area of a Rectangle Can you find the areas of these rectangles? 5 cm 15 cm 2 2 cm 3 cm 14 cm 2 7 cm 7 m 49 m 2 7 m

Area of a Rectangle Can you think of a way to find the area of this shape? 5 cm 6 cm 7 cm 3 cm 12 cm

Area of a Rectangle Split the shape into rectangles? 5 cm 6 cm 7 cm 3 cm 12 cm

Area of a Rectangle Find the area of each rectangle? 5 cm 5 × 6 = 30 cm 2 7 × 3 = 21 cm 2 6 cm 7 cm 3 cm

Area of a Rectangle Add the areas together to find the area of the complete shape? 30 + 21 = 51 cm 2 30 cm 2 21 cm 2

Area of a Rectangle Can you find the areas of these shapes? 2 8 + 35 = 43 cm 2 cm 8 6 m cm 2 4 cm 18 m 2 3 m 4 m 11 cm 35 cm 2 7 cm 4 m 2 1 m 4 m 18 + 4 = 22 m 2 5 cm

Area of a Rectangle Here is a challenge can you work out the area of this shape with a hole in it? 2 cm 5 cm 10 cm Clue: Take the area of the hole from the area of the whole! 50 cm 2 – 10 cm 2 = 40 cm 2

Remember: Area of a rectangle = length × width length width Split more complicated shapes into rectangles and find the area of each rectangle then add them together. Over to you.