6. What is the diameter of each of these circles? a) radius 4cm d) radius 7cm
b) radius 9cm e) radius 12.2cm
7. Find the radius of each of these circles if the diameter is: a) 20cm d) 29cm
b) 15cm e) 18.4cm
c) radius 3.5cm f) radius 6.8cm
c) 14.2cm f) 17cm
8. Using your compasses, construct circles with the following diameters on centimetre squared paper.
a) 8cm b) 9.4cm c) 7.2cm d) 3cm ? e) 5cm
f) Can you work out the approximate area of each circle by counting the squares? 9. What is the approximate area of this circle in cm2
10. Using your compasses, construct circles with the following radii. a) 2cm
b) 3.5cm c) 1.9cm d) 4.1cm
e) 2.6cm
Circle Challenge 11. a) How many radii are in a diameter? b) Name the line that joins the centre point to the circumference of the circle. c) What is the name for the perimeter of a circle?