1. Starters

2. Starter: Matching circumferences
Paul measured some circular objects but got them muddled up and measured one incorrectly.
Work out the correct values and correct the mistake.
Diameter
Circumference
3 cm
5 cm
25 cm
16 cm
4 m
6.5 cm
10 cm
5 mm
8 cm x
15.5 cm
9.4cm
78cm
50cm
20.5cm
13m
31cm
1.6cm
Choose from: cm 9.4cm 1.6cm 8cm 50cm 13m 78cm 31cm

3. Starter: What is a prism?
No – just 2 dimensional
Yes – 3D and exactly the same cross-section
No – 3D but not exactly the same cross-section

4. Starter: Matching the areas
For each of these 2 dimensional shapes, match it with the correct area. All measurements are in cm. 12 6 5 14 14 4 20 10 10 15
Choose from: 68 cm2 70 cm2 72 cm cm cm2 80 cm2

5. Example Questions

6. Practice: Surface area of a cylinder
Find the surface area of these cylinders: 1) Radius 7 cm and Height 5 cm
2) Radius 10 cm and Height 15 cm
3) Diameter 4 m and Height 8 m
4) Radius 50 mm and Height 10 cm
5) Diameter 20 cm and Height 0.7 m
Answers: 1) cm2 2) 1570 cm2
3) m2 4) 471 cm2
5) 5024 cm2 or m2
Challenge: 47 cm
Challenge
A cylinder has surface area of 942 cm2. Its radius is 3cm. What is its height?

7. Practice: Volume of a cylinder
Find the volume of these cylinders: 1) Radius 10 cm and Height 15 cm
2) Diameter 6 m and Height 12 m
3) Radius 20 mm and Height 5 cm
4) A cylinder has volume of 7693 cm3. Its radius is 7cm. What is its height?
5) The volume of a cylinder is cm3. Its height is 100cm. What is its radius?
Answers: 1) cm3 2) m3 3) 62.8 cm3 4) 50 cm 5) 2.5 cm

8. Practice: Volume of a prisms
Find the volume of these prisms: cm
8cm
23cm
6 cm
8cm
20cm
9 cm
11cm
7cm
5.5 cm
6cm
10cm
Answers: 480cm cm cm cm3