Do now: Work out the circumferences and areas of these circles 10 cm 12 cm 9 cm 2 cm 1.5 cm.
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Do now: Work out the circumferences and areas of these circles 10 cm 12 cm 9 cm 2 cm 1.5 cm
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Transcript of Do now: Work out the circumferences and areas of these circles 10 cm 12 cm 9 cm 2 cm 1.5 cm.
Do now: Work out the circumferences and areas of these circles
10 cm
12 cm
9 cm
2 cm
1.5 cm
How well did you do?
10 cm
12 cm
9 cm
2 cm
1.5 cmC = 31.4 cm
C = 56.5 cmC = 37.7 cm
C = 9.4 cm
C = 6.3 cm
How well did you do?
12 cm
9 cm
2 cm
1.5 cm
A= π × 52
A = 78.5 cm2
5 cm
A= π × 62
A = 113.0 cm2
A= π × 12
A = 3.1 cm2
A= π × 92
A = 254.3 cm2
A= π × 1.52
A = 7.1 cm2
Circumference = π × diameterC=πd
OR
Circumference = 2 × π × radiusC=2πr
Area = π × radius × radius A=πr2
Did you remember these important formulae?You are expected to remember these in your GCSE exam.
diameter
radi
us
