1. www.mathsrevision.com Level 2 Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty1 The Circle Main Parts of a Circle Formula for Circumference

2. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 2 Starter Questions 7cm www.mathsrevision.com Level 2

3. www.mathsrevision.com Level 2 Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty3 Main part of a Circle Learning Intention o identify the main parts of a circle. We are learning to identify the main parts of a circle. Success Criteria 1. Understand the terms circumference, diameter and radius. 2. Identify them on a circle. 3. Calculate the circumference using formula.

4. www.mathsrevision.com Level 2 Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty4 Main parts of the circle Main part of a Circle radius O Circumference Diameter

5. www.mathsrevision.com Level 2 Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty5 Main part of a Circle 10cm 2cm

6. www.mathsrevision.com Level 2 Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty6 Main part of a Circle Your turn Exercise 1 Chapter 19 Page 228

7. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 7 Starter Questions 5cm www.mathsrevision.com Level 2

8. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 8 Stars In Your Eyes “Today Matthew we are going to be” Archimedes of Syracuse www.mathsrevision.com Level 2

9. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 9 The Greek mathematician Archimedes of Syracuse (287- 212 BC) who flourished in Sicily is generally considered to be the greatest mathematician of ancient times. He is credited with determining the relationship between the diameter and the circumference of a circle. This was first recorded by Archimedes in the book Measurement of a Circle (225 BC). In this investigation we are going to attempt to follow Archimedes steps and arrive at the equation for determining the circumference for any given circle. History of Circles 75 years old 22931 years old www.mathsrevision.com Level 2

10. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 10 Parts of the Circle Circumference O O = centre of circle The radius is measured from the centre of the circle to the edge. radius diameter The diameter is measured from one edge to the other passing through the centre of the circle. www.mathsrevision.com Level 2

11. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 11 Circle Investigation Construct a table shown below to enable us to record our results. www.mathsrevision.com Level 2

12. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 12 Investigation of the Circle To find a relationship between the diameter and circumference of a given circle. How can we measure the diameter and circumference O Our Investigation Question ? www.mathsrevision.com Level 2

13. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 13 Measuring the Diameter of a circle The diameter is the largest distance between one side of a circle to the other passing through the centre O. O O Use a ruler www.mathsrevision.com Level 2

14. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 14 Measuring the Circumference of a circle Flexible tape measure Take a tape measure and put it round the circle Read off the measurement O www.mathsrevision.com Level 2

15. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 15 Measuring the Circumference of a circle Roll along an even surface One complete rotation equals the length of the circumference Be careful to avoid slip! Starting point End point www.mathsrevision.com Level 2

16. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 16 Circle Investigation www.mathsrevision.com Level 2

17. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 17 Circle Investigation Using your results write down, in your own words, an approximate relationship between the circumference and diameter for a given circle. “Circumference approximately equals three and bit diameters” Actual value is 3.14 which we write as  Pronounced “Pi” www.mathsrevision.com Level 2

18. Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Wednesday, 19 August 2015Created by Mr Lafferty 18 Chapter 19 Exercise 2 Page 229 Q2 Circle Investigation www.mathsrevision.com Level 2