Geometry Perimeter of 2 D Shapes Starter Its

Geometry Perimeter of 2 D Shapes

Starter: It’s a Match Task: Match up the name to its shape. There may be more than one answer as well as some red herrings! Triangle Square Rectangle Parallelogram Trapezium Extension: Choose a shape and describe its properties using the keywords vertices, faces and edges, lines of symmetry, parallel, angles.

Starter: It’s a Match - Answers Rectangle Triangle Trapezium Square Parallelogram

What Is Perimeter? Pause for Thought What is ‘perimeter’? Can you think of a definition? To calculate the perimeter, we add up the lengths of all of its sides. The perimeter of a shape is the total distance around its edge. Pause for Thought How do we calculate perimeter?

When Will I Need Perimeter? Pause for Thought Can you think of any real-life examples of when you might need to calculate a perimeter? Gardening Decorating houses Building projects Farming Wrapping presents Fencing off an area

Calculating Perimeter Calculate the perimeter of this square. 5 cm 5 + 5 + 5 = 20 cm or 5 × 4 = 20 cm Too easy? Try this! Calculate the perimeter of a square where one side is equal to 4 + 2 × 2 cm. 4+2× 2=8 8+8+8+8 or 8 × 4 = 32 cm

Calculating Perimeter Calculate the perimeter of this rectangle. 10 cm 4 cm 10 + 4 + 10 + 4 = 28 cm or (10 + 4) × 2 = 28 cm Too easy? Try this! Calculate the perimeter of a rectangle where the width is 5 cm and the length is 0. 2 m. Give your answer in centimetres. 0. 2 m = 20 cm (20 + 5) × 2 = 50 cm

Calculating Perimeter Calculate the perimeter of this triangle. 8 cm 4 cm 10 + 8 + 4 = 22 cm 10 cm Too easy? Try this! Calculate the perimeter of an equilateral triangle, which has a side length of 6 cm. 6 × 3 = 18 cm

Calculating Perimeter Calculate the perimeter of this parallelogram. 11 cm 7 cm 11 + 7 + 11 + 7 = 36 cm or (11 + 7) × 2 = 36 cm Too easy? Try this! Calculate the perimeter of a parallelogram where the width is 0. 15 m and the length is 20 cm. Give your answer in centimetres. 0. 15 m = 15 cm (20 +15) × 2 = 70 cm

Calculating Perimeter Calculate the perimeter of this trapezium. 6 cm 7 cm 12 + 7 + 6 + 7 = 32 cm 12 cm Too easy? Try this! Calculate the perimeter of a trapezium which has the measurements of 10 cm, 8 cm, 0. 12 m and 70 mm. Give your answer in centimetres. 0. 12 m = 12 cm 70 mm = 7 cm 10 + 8 + 12 + 7 = 37 cm

Calculating Perimeter What is the total perimeter for the following shape? 3 cm 4 cm Pause for Thought What information is missing? 9 cm 10 cm 6 cm 12 + 10 + 3 + 4 + 9 + 6 = 44 cm