Area of a Circle

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Area of a Circle
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• Area of a Circle pr²
• 
  Apx6²
• 
  Apx36
• 
  A 113.1 (to 1 dec pl)

r6cm
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What if the shape is more complex?

• 
  
  

First find the area of the large circle. Second,
find the area of the small circle. Then subtract
the area of the small circle from the area of the
large circle to find the answer.
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How do you find the area of a circle given the
diameter?
If d20cm, first find rd / 2
r10cm Then proceed as
before.. A p r² A p x 10² A p x 100 A 314.2
(to 1 dec pl)
d20cm
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How do you find the radius given the area?
Area p r ² 15.21 p r ² r ² 15.21 4.841.
p vAns 2.2 cm
Area 15.21cm²
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• Now try some of your own.