1. The Olympic Rings

2. Starter Activity Traffic Lights activity Pupils each have a red, amber and green card. When I have asked a question hold up one of your cards according to the following definitions: Green – I know the answer Amber – I am not sure Red – I do not know the answer I will then ask for responses and confirm the answer. Ask questions to recap knowledge on radius, diameter, circumference and area.

3. Objectives To use calculations of radius, diameter, circumference and area to investigate the dimensions of the Olympic Rings. To apply these formulae to calculations about particular Olympic sports.

4. History The rings were adopted in 1913. The five rings represent the five major regions of the world: Africa, the Americas, Asia, Europe, and Oceania. Every national flag in the world includes at least one of the five colours, which are blue, yellow, black, green, and red.

5. Diameter and Radius The distance across a circle through its centre is called its diameter, D. The radius, R of a circle is the distance from the centre of a circle to a point on the edge of the circle. So a circle's diameter is twice as long as its radius: D = 2 × R. diameter, D radius, R

6. The distance around a circle is its circumference, C = 2 ×  × R. The area, A, of a circle is: A =  × R × R or A =  × R 2 Pi, , is the ratio of the circumference of a circle to its diameter.  ≈  22/7  ≈  3.1415926535... Circumference and Area area, A

7. 1.The diameter of the women’s discus is 21 cm. What is its area? 2.The area of a weight is 2000 cm 2. What is its radius? 3.The radius of a men’s discus is 11 cm. What is its area? 4.The diameter of a bicycle wheel is 0.75 m. What is the area of the wheel? Questions (use  = 3.14)

8. Questions Find the total circumference of the outer parts of the Olympic rings. Find the total circumference of the inner parts of the Olympic rings. Find the total area of the Olympic rings. Use the ring dimensions below to answer the questions. Remember there are 5 rings in total. 10cm 110cm

9. Answer to Question 1 Find the total circumference of the outer parts of the Olympic rings CircumferenceC = 2 ×  × R DiameterD = 2 × R Circumference of one outer ring C 1 = 2 ×  × (D/2) =  × D C 1 = 3.14 × 110cm = 346cm Circumference of five outer rings C 5 = 5 × C 1 = 5 × 346cm = 1730cm 10cm 110cm

10. 10cm 110cm Answer to Question 2 Find the total circumference of the inner parts of the Olympic rings CircumferenceC = 2 ×  × R DiameterD = 2 × R Circumference of one inner ring C 1 = 2 ×  × (D/2) =  × D C 1 = 3.14 × 90 cm = 283 cm Circumference of five inner rings C 5 = 5 × C 1 = 5 × 283 cm = 1415 cm Diameter of the inner ring: D = 110 cm – 20 cm = 90 cm

11. Answer to Question 3 Find the total area of the Olympic rings Area of one inner circle A (I)1 =  × R (I)1 2 = 3.14 × (45cm) 2 = 6358cm 2 Area of one outer circle A (o)1 =  × R (o)1 2 = 3.14 × (55cm) 2 = 9499cm 2 Area of one ring A 1 = A (o) -A (I)1 = 9499cm–6358cm = 3141cm 2 Area of the five rings A 5 = 5 × A 1 = 5 × 3141cm 2 = 15705cm 2 Radius of the inner ring, R (I)1 = 45cm Radius of the outer ring, R (o)1 = 55cm 10cm 110cm

12. Bicycle – Questions Q1. The rim of a bicycle wheel has a radius of 33 cm. What is the circumference of the rim of the wheel (to one decimal place)? Q2. The rim of a bicycle wheel has a diameter of 64cm. When the tyre is mounted on the wheel, the diameter of the wheel increases as shown on the right. How much does the circumference of the bicycle wheel increase after the tyre is mounted (to one decimal place)? 33cm 64cm 3cm

13. Bicycle – Questions Q3. The wheel of Billy’s bike has a circumference of 2 m. How many metres will the bicycle travel when the wheel has made 400 revolutions? Q4. A bicycle wheel has a diameter of 75 cm. How many revolutions will the wheel make when it has rolled 1 km? Q5. A racer’s bicycle wheel has a diameter of 80 cm and makes 360 revolutions per minute. How far will the bicycle travel in 5 minutes? Note: The distance a wheel rolls in one revolution is equal to its circumference.

14. Homework – Drawing the Olympic rings The rings are 11 blocks wide and 1 block thick (graph paper needs to be at least 37 blocks). 1.Count at least 7 blocks down and draw a horizontal line on the graph paper (the centerline for the three upper rings). 2.On the centre line, count around 8 blocks. Mark a small cross (the center of ring 1). 3.From Ring 1 count 12 blocks and mark a small cross for Ring 2. 4.From Ring 2 count 12 blocks and mark a small cross for Ring 3. 5.To locate the center for Ring 4: start at the center of Ring 1, count over 6 blocks, then down 5.5 blocks. Mark a cross at this point.

15. Homework – Drawing the Olympic rings 6.To locate the center for Ring 5: start at the center of Ring 2, count over 6 blocks, then down 5.5 blocks. Mark a cross here. 7.Set the compass to a radius of 5.5 blocks (diameter of 11 blocks). Draw the five large outer circles at each of the center points. 8.Set the compass to a radius of 4.5 blocks (diameter of 9 blocks). Draw the five small inner circles at each of the center points. 9.Erase small sections of the circles to create the illusion of a chain. 10.Darken the object lines and colour the rings according to the diagram.

16. Plenary Key words Make a glossary of the day’s key words. Share your glossary with your partner. Add any words to your list you think are important.

17. Credits and Copyright Copyright You may not reproduce, modify, copy, make available or distribute or otherwise use any of the images in this presentation without written permission from the owner of the relevant intellectual property rights. Written material in the presentation may, however, be modified according to the needs of the user. Some of the images used in this presentation have been provided by Getty Images who support London’s Bid to host the 2012 Olympic and Paralympic Games. Credits Developed by Nicola Mckie