Think about how you would draw this diagram using compasses. What would you make the radius of the circle? Why?
Draw a circle with the a radius of 6 cm What will you draw next? Where will you place the pin? What will you make the radius?
Once you have drawn it – can you find the area of each of the different colours? What is the ratio of the areas red:orange:yellow?
Using what you have already done, can you work out the area of the different colours in this shape? What fraction of the circle is red? Orange? Yellow? Green?
And this one? Can you predict what will happen?
What if there were n colours? Why?