1. Calculate the circumference and area of the following circles (use pi = 3.1):

 

a. 
b.

c.

d.

2. Find the area that is shaded red. (Use pi = 3.1)

3. For the two circles (lengths in metres) find, using pi = 3.1:

a. the shaded area.

b. the difference between the circumference of the large and small circles.

 

4. A garden contains a circular section planted with roses. 
The gardener needs to work out how many paving stones would be needed to put around the outside of the garden i.e. around the circumference. 
a. The diameter of this rose bed is 20 metres,using pi = 3.1, what would be its circumference? 
The gardener also needs to know the area in order to buy some fertiliser. 
b. What would be the area of the circular garden?
c. If each bag of fertiliser covers 20 square metres how many bags of fertiliser should be bought?