Perimeter & Area

1. Perimeter & Area Perimeter Rectilinear & Circle Area Rectilinear Shapes Area of a Circle www.mathsrevision.com Composite Area Created by Mr. Lafferty Maths Dept.

2. Starter Questions Q1. Solve the equation below ao Q2. Find the missing angles bo Q3. Find the average of the numbers below www.mathsrevision.com 2,5,6,7 Q4. Which is the better deal or Created by Mr. Lafferty Maths Dept.

3. Perimeter Learning Intention Success Criteria • Understand the term perimeter of a shape. • 1. We are learning the term perimeter of a shape. www.mathsrevision.com 2. Calculate the perimeter of a shape. Created by Mr. Lafferty Maths Dept.

4. Perimeter What is perimeter ? www.mathsrevision.com Hint answer is on the screen ! Created by Mr. Lafferty Maths Dept.

5. Perimeter www.mathsrevision.com Perimeter Created by Mr. Lafferty Maths Dept.

6. Perimeter www.mathsrevision.com Perimeter Created by Mr. Lafferty Maths Dept.

7. Perimeter Perimeter is the distance round the outside of a2D shape www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

8. Perimeter 6cm Calculate the perimeter of the rectangle below. 3cm Demo www.mathsrevision.com Perimeter = 6 + 3 + 6 + 3 18cm = Created by Mr. Lafferty Maths Dept.

9. x m 4 m 9 m 8 m 4 m Perimeter 12 m Perimeter Problem Below is a drawing of a school building. Calculate the perimeter. x = 12 – 9 =3 m www.mathsrevision.com = 12 + 8 + 3 + 4 + 9 + 4 = 40 m Created by Mr. Lafferty Maths Dept.

10. Perimeter The desks below have been arranged in a certain way. Find the perimeter of each design. 2cm 2cm www.mathsrevision.com 2cm 2cm Created by Mr. Lafferty Maths Dept.

11. Circumference Example : Find the length of the circumference (Perimeter) of each circle 2cm 10cm www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

12. Perimeter ExampleFind the perimeter for the semi-circle shape ? Solution www.mathsrevision.com 180o Created by Mr Lafferty

13. Solution Perimeter ExampleFind the perimeter of the shape below ? 8cm 90o www.mathsrevision.com Created by Mr Lafferty

14. 5 cm 20cm Perimeter Example : Find the perimeter of this shape Perimeter = 3 sides + semicircle www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

15. Perimeter Now try N5 Lifeskills Ex1 Ch6 (page 54) www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

16. Starter Questions Q1. What is the time difference 09:28 and 11:55 Q2. Convert 23metres to (a) cm (b) mm www.mathsrevision.com Q3. The answer to the question is 180. What is the question. Created by Mr. Lafferty Maths Dept.

17. Area of a Rectangle Learning Intention Success Criteria • Remember area formula for a rectangle. • 1. Develop a formula for the area of a rectangle. • Apply formula correctly. • (showing working) www.mathsrevision.com • Answer containing • appropriate units Created by Mr. Lafferty Maths Dept.

18. Revision of Area The Square The Rectangle The RAT l b h l l b www.mathsrevision.com Area = l x l Area = l x b Area = ½b x h Perimeter = 2l + 2b Perimeter = 4 x l Created by Mr.Lafferty

19. Area of a Rhombus This part of the rhombus is half of the small rectangle. d D www.mathsrevision.com Created by Mr.Lafferty

20. Area of a Kite d D Exactly the same process as the rhombus www.mathsrevision.com Created by Mr.Lafferty

21. Rhombus and Kite Area Example : Find the area of the shapes. 2cm 4cm 5cm 9cm www.mathsrevision.com Created by Mr.Lafferty

22. Rhombus and Kite Area Example : Find the area of the V – shape kite. 4cm www.mathsrevision.com 7cm Created by Mr.Lafferty

23. Parallelogram Area h b Important NOTE h = vertical height www.mathsrevision.com Created by Mr.Lafferty

24. Parallelogram Area Example 1 : Find the area of parallelogram. 3cm 9cm www.mathsrevision.com Online Demo Created by Mr.Lafferty

25. Rectilinear Area Now try N5 Lifeskills Ex2 Ch6 (page 56) www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

26. Starter Questions www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

27. Area of a Circle Learning Intention Success Criteria • Know the formula for the area of a circle. • 1 We are learning how to calculate the area of a circle. 2. Be able show appropriate working. www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

28. Peeling an orange Area of a Circle A circumference A B x x O O www.mathsrevision.com • What do we call the distance OA in terms of • the large circle. • What do we call the distance AB in terms of the large circle.

29. Peeling an orange Area of a Circle A circumference A B x x O O www.mathsrevision.com • What do we call the distance OA in terms of • the large circle. • What do we call the distance AB in terms of the large circle.

30. A B x O Area of a Circle • What is the formula for the area • of a right-angle triangle. • Use this formula to work out • the area for a circle. www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

31. If we break the circle into equal sectors And lay them out side by side We get very close to a rectangle. 1 8 2 2 7 1 3 6 5 8 6 4 4 3 7 5 Area of a Circle www.mathsrevision.com Demo Created by Mr Lafferty

32. If we cut the sectors Thinner and thinner then we get closer and closer to a rectangle. Hence we can represent the area of a circle by a rectangle. 8 6 4 2 3 7 1 5 thinner and thinner sectors Area of a Circle www.mathsrevision.com Created by Mr Lafferty

33. Area of a Circle www.mathsrevision.com But the area inside this rectangle is also the area of the circle Area = πr2 Created by Mr Lafferty

34. Solution Area of a circle Q.Find the area of the circle ? 4cm www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

35. Solution Area of a circle • The diameter of the circle is 60cm. • Find area of the circle? www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

36. Area of a Circle Now try N5 Lifeskills Ex3 Ch6 (page 57) www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

37. Starter Questions Q1. Why is Q2. What is the time difference 07:54 and 13:36 Q3. www.mathsrevision.com Q4. Convert 45.1 metres to (a) cm (b) mm Q5. The answer to the question is 90. What is the question. Created by Mr. Lafferty Maths Dept.

38. Area of a Composite Made up of Simple shapes Learning Intention Success Criteria • Use knowledge gained so far to find the area of more complicated shapes.. • 1. We are learning to find area for more complicated shapes. www.mathsrevision.com • Show appropriate working. Created by Mr. Lafferty Maths Dept.

39. 9cm 6cm 8cm 5cm Area of a Composite Calculate the area of this shape Total Area = 72 + 30 = 102cm2 A = l x b A = 9 x 8 www.mathsrevision.com A = l x b A = 72cm2 A = 6 x 5 A = 30cm2 Created by Mr. Lafferty Maths Dept.

40. 8cm 10cm 6cm 12cm Area of a Composite Calculate the area of this shape www.mathsrevision.com

41. 8cm 10cm 6cm 4cm Area of a Composite Calculate the area of this shape Total Area = 80 + 24 = 104cm2 A = l x b www.mathsrevision.com A = 8 x 10 A = l x b A = 80cm2 A = 4 x 6 A =24cm2

42. 5cm 6cm Area of a Composite Calculate the area of this shape Rectangle 1 16cm A = l x b A = 16 x 5 5cm A = 80cm2 www.mathsrevision.com Rectangle 2 A = l x b Total Area A = 6 x 5 = 80 + 30 =110cm2 A = 30cm2 Created by Mr. Lafferty Maths Dept.

43. 5 cm 20cm Composite Area Example 1 : Find the area of the shape Area = rectangle + semicircle www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

44. Composite Area Example 2 : A circle is contained in a square. Find the grey shaded area below. Area = square - circle 8cm www.mathsrevision.com Created by Mr. Lafferty Maths Dept.

45. Have you updated your Learning Log ? Composite Area Now try N5 Lifeskills Ex4 Ch6 (page 59) www.mathsrevision.com Are you on Target ? I can ? Are you on Target ? I can ? Are you on Target ? I can ? Created by Mr. Lafferty Maths Dept.