GCSE Maths (AQA)
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Area of a Circle
- The area of a circle is proportional to the radius squared
- The formula for the area of a circle is pi times the radius squared
- Pi is the ratio between the circumference and diameter of a circle
- The formula can be shown to be correct by splitting a circle into sectors and constructing a rectangle from them
- As the number of sectors increases, the shape becomes closer to a true rectangle
- The area of the rectangle is equal to the area of the circle
- The area of a circle can be calculated using the formula pi times the radius squared
- Example: Calculate the area of a circle with a radius of 15 cm using the formula pi times the radius squared
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