Use pi, π = 3.1 for all of the questions in this exercise.
1. For the circle shown below, where O is the centre, name:
a. Three radii
b. A diameter
2. What is the diameter of the following circles?
|
a.
|
b.
|
3. What is the radius of the following circles?
|
a.
|
b.
|
4. Complete the table below for these common circular objects (measured to 1 decimal place) :
|
Object
|
Circumference
|
Diameter
|
Circumference ÷ diameter
|
|
| a | Soccer ball |
21.4 cm
|
6.8 cm
|
|
| b | Can lid |
6.2 cm
|
2 cm
|
|
| c | Two dollar coin |
24 mm
|
7.7 mm
|
|
| d | Mars |
21310 km
|
6790 km
|
|
| e | Clock |
54.7 cm
|
17.4 cm
|
What name is given to this ratio?
5. Find the circumferences and areas of the following circles.
|
a
|
b
|
 |
 |
6.
a. The radius of a circular desk is 1.3 metres, what is its diameter?
b. Find the area of a circle with a diameter of 10 centimetres.
c. What is the radius of a circle with a circumference of 34.2 cm?
d. What is the diameter of a circle with an area of 49.6 cm2?
7. Find the area that is shaded red.
8. Find the volumes of the following solids:
a. A cylinder with a circular base of radius 5 centimetres and a height of 10 centimetres.
b. A sphere with a radius of 6 centimetres.
c. A cone with a base of 5 cm and a height of 10 cm.
