Area of a rectangle Area of composite shapes Area of a right-angled triangle Simple Areas

Starter Questions Starter Questions 34 o

Area of a Rectangle Learning Intention Success Criteria 1.To be able to state area formula for a rectangle. 1. To come up with a formula for the area of a rectangle. 2.Use the formula to solve problems. 2.Apply formula correctly. (showing working) (showing working) 3.Answer containing appropriate units appropriate units

Problem… General Jack’s Carpets Only £5 a square metre! How much for this one? ?

3 rows of 6 squares Problem… 6 square metres = 3 x 6= 18 square metres = 1 square metre 3 m 6 m 1m How much for 18 square metres? 18 x £5 = £90

Area of a rectangle 6 = 18 m² 3 m 6 m 3 6 Area =lengthx breadth length breadth x 3

Example 1 11 cm 6 cm Area = length x breadth A = l x b A = 11 x 6 A = 66 cm² Find the area of the rectangle

Example 2 12 cm Area = length x breadth A = l x b A = 12 x 12 A = 144 cm² Find the area of the square

Starter Questions Starter Questions o

Learning Intention Success Criteria 1.Know area of a right-angled triangle formula Use the area of a rectangle formula to help us to come up with a formula to calculate the area of any right-angled triangle. 1. Use the area of a rectangle formula to help us to come up with a formula to calculate the area of any right-angled triangle. 2.Use formula to work out area of triangle. 3.Show all working and units. Area of A Right-Angled Triangle

Area of a right-angled triangle Area of rectangle = l x b= 28 cm² 4 cm 7 cm = 7 x 4 Area of triangle = 14 cm² = ½ x 28 = ½ x Area of rectangle

Area of triangle Short cut 4 cm 7 cm Area of triangle = 14 cm²= ½ x 28 = ½ x 7 x 4 Area Δ =x basex height ½ base height

Example 1 10 cm 15 cm Area Δ=½ x base x height AΔ =½ x b x h AΔ = ½ x 15 x 10 AΔ = 75 cm² Find the area of the triangle

Example 2 12 cm 8 cm Area Δ=½ x base x height AΔ =½ x b x h AΔ = ½ x 8 x 12 AΔ = 48 cm² Find the area of the triangle

Now try worksheet Exercise 1 Area of a right-angled triangle

Starter Questions Starter Questions 34 o

Area of a Composite Learning Intention Success Criteria 1.To be able to use knowledge gained so far to find the area of more complicated shapes.. 1. To use knowledge to find area of more complicate shapes. 2.Show appropriate working. Made up of Simple shapes

? Composite shapes 6 cm 10 cm 13 cm ? 3 cm

6 cm ? 10 cm (1) (2) Area (1) = l x b= 60 cm²= 10 x 6 Area (2) = 9 cm² = ½ x 3 x 6 = ½ x b x h Area of shape = (1) + (2)= 69 cm²= cm Composite shapes

Example 1 Area (1)= =15 x 8 Area (2) = l x b l x b = 120 cm² =9 x 3 = 27 cm² Area of shape = (1) + (2) = = 147 cm² 15cm 11cm 6cm 3cm (1) (2) ? 9cm 8cm ? Find the area of the shape

Example 2 Area (1)= =20 x 12 Area (2) = l x b 12cm 20cm10cm 6cm (1) (2) l x b = 240 cm² =10 x 6 = 60 cm² Area of shape = (1) – (2) = = 180 cm² Find the area of the shape

Now try worksheet Exercise 2 Composite shapes