The Circle www mathsrevision com S 5 Int

The Circle www. mathsrevision. com S 5 Int 1 Main Parts of a Circle Investigation of the Ratio of Circle Circumference of the circle Composite shapes Perimeter

Starter Questions www. mathsrevision. com S 5 Int 1 7 cm Sunday, November 1, 2020 Created by Mr Lafferty 2

Main Parts of a Circle www. mathsrevision. com S 5 Int 1 Learning Intention Success Criteria 1. To revise the basics of the circle. 01 -Nov-20 1. Know the terms circumference, diameter and radius. 2. Identify them on a circle. 3. Calculate the circumference using formula. Created by Mr. Lafferty Maths Dept.

Main part of a Circle www. mathsrevision. com S 5 Int 1 Main parts of the circle O Sunday, November 1, 2020 Created by Mr Lafferty 4

Main part of a Circle www. mathsrevision. com S 5 Int 1 2 c m m c 0 1 Sunday, November 1, 2020 Created by Mr Lafferty 5

Main part of a Circle www. mathsrevision. com S 5 Int 1 Now try Ex Int 1 TJ Book 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Starter Questions www. mathsrevision. com S 5 Int 1 5 cm Sunday, November 1, 2020 Created by Mr Lafferty 7

Stars In Your Eyes www. mathsrevision. com S 5 Int 1 “Today Matthew we are going to be” Archimedes of Syracuse Sunday, November 1, 2020 Created by Mr Lafferty 8

History of Circles www. mathsrevision. com S 5 Int 1 75 years old The Greek mathematician Archimedes of Syracuse (287 - 212 BC) who flourished in Sicily is S 5 Int 1 ly 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. Sunday, November 1, 2020 Created by Mr Lafferty 9

Parts of the Circle www. mathsrevision. com S 5 Int 1 Circumference The radius is measured from the centre of the circle to the edge. radius O diameter O = centre of circle The diameter is measured from one edge to the other passing through the centre of the circle. Sunday, November 1, 2020 Created by Mr Lafferty 10

Circle Investigation www. mathsrevision. com S 5 Int 1 Construct a table shown below to enable us to record our results. Sunday, November 1, 2020 Created by Mr Lafferty 11

Investigation of the Circle S 5 Int 1 www. mathsrevision. com Our Investigation O To find a relationship between the diameter and circumference of a given circle. Question ? How can we measure the diameter and circumference Sunday, November 1, 2020 Created by Mr Lafferty 12

Measuring the Diameter of a circle www. mathsrevision. com S 5 Int 1 O Use a ruler O The diameter is the largest distance between one side of a circle to the other passing through the centre O. Sunday, November 1, 2020 Created by Mr Lafferty 13

Measuring the Circumference of a circle www. mathsrevision. com S 5 Int 1 Flexible tape measure O Take a tape measure and put it round the circle Read off the measurement Sunday, November 1, 2020 Created by Mr Lafferty 14

Measuring the Circumference of a circle www. mathsrevision. com S 5 Int 1 Roll along an even surface End point Starting point One complete rotation equals the length of the circumference Be careful to avoid slip! Sunday, November 1, 2020 Created by Mr Lafferty 15

Circle Investigation S 5 Int 1 Sunday, November 1, 2020 Created by Mr Lafferty 16

Circle Investigation www. mathsrevision. com S 5 Int 1 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 π Pronounced “Pi” Sunday, November 1, 2020 Created by Mr Lafferty 17

Circle Investigation www. mathsrevision. com S 5 Int 1 No Exercise 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Starter Questions www. mathsrevision. com S 5 Int 1 4 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Main Parts of a Circle www. mathsrevision. com S 5 Int 1 Learning Intention Success Criteria 1. To revise the basics of the circle. 01 -Nov-20 1. Know the terms circumference, diameter and radius. 2. Identify them on a circle. 3. Calculate the circumference using formula. Created by Mr. Lafferty Maths Dept.

Main Parts of a Circle www. mathsrevision. com S 5 Int 1 Main parts of the circle O Circumference 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Calculating the Circumference Example : Find the length of the circumference of each circle 2 c cm m 10 www. mathsrevision. com S 5 Int 1 01 -Nov-20 Created by Mr. Lafferty Maths Dept. (Perimeter)

Calculating the Circumference www. mathsrevision. com S 5 Int 1 Q. Calculate the curved part of this shape. Solution 6 m 90 o Sunday, November 1, 2020 Created by Mr Lafferty 23

Main part of a Circle www. mathsrevision. com S 5 Int 1 Now try Ex Int 1 TJ Book 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Starter Questions www. mathsrevision. com S 5 Int 1 4 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Composite Perimeter www. mathsrevision. com S 5 Int 1 Learning Intention Success Criteria 1. To give some examples of problems that we can solve by applying our knowledge of circles and of the course so far. 01 -Nov-20 1. Recall knowledge of circles so far. 2. Solve mixed problems by applying all our knowledge so far. Created by Mr. Lafferty Maths Dept.

Composite Perimeter www. mathsrevision. com S 5 Int 1 Things to think about when doing exercise. The perimeter of a semicircle ……. Find whole circle then half it ! The perimeter of a quarter circle ……. Find whole circle then quarter it ! Composite perimeter ……. Find each perimeter and add them together ! 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Composite Perimeter www. mathsrevision. com S 5 Int 1 Find the perimeter for the semi-circle shape ? Q. Solution 180 o Sunday, November 1, 2020 Created by Mr Lafferty 28

Composite Perimeter www. mathsrevision. com S 5 Int 1 Q. Find the perimeter of the shape below ? Solution 8 cm 90 o Sunday, November 1, 2020 Created by Mr Lafferty 29

Composite Perimeter S 5 Int 1 www. mathsrevision. com Example 1 : Find the perimeter of this shape Perimeter = 3 sides + semicircle 5 cm 20 cm 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Composite Perimeter www. mathsrevision. com S 5 Int 1 Now try Ex Int 1 TJ Book 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Starter Questions www. mathsrevision. com S 5 Int 1 2 cm 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Composite Area www. mathsrevision. com S 5 Int 1 Learning Intention Success Criteria 1. To give some examples of problems that we can solve by applying our knowledge of circles and of the course so far. 01 -Nov-20 1. Recall knowledge of circles so far. 2. Solve mixed problems by applying all our knowledge so far. Created by Mr. Lafferty Maths Dept.

Composite Area S 5 Int 1 www. mathsrevision. com Example 1 : Find the area of the shape Area = rectangle + semicircle 5 cm 20 cm 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Composite Area S 5 Int 1 www. mathsrevision. com Example 1 : Find the area of the red part. Area = Big Circle – Small Circle 4 cm 10 cm 01 -Nov-20 Created by Mr. Lafferty Maths Dept.

Composite Area www. mathsrevision. com S 5 Int 1 Example 2 : A circle is contained in a square. Find the grey shaded area below. 8 cm 01 -Nov-20 Area = square - circle Created by Mr. Lafferty Maths Dept.

Composite Area www. mathsrevision. com S 5 Int 1 Now try Ex Int 1 TJ Book 01 -Nov-20 Created by Mr. Lafferty Maths Dept.