1.8 KiB
1.8 KiB
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Finding Circumference of a Circle When Given the Area |
Background information
What is circumference?
The length of enclosing boundary of a curved geometric figure.
What is area?
Area is measure of how much space there is on a flat surface.
Question: Find circumference of circle when area of circle is given?
Steps:
- area of circle = π × r2, so we shall find radius of circle from with this formulae.
- circumference of circle = 2 × π r, and put radius in this formulae to calculate circumference.
Example, Question) Find circumference of a circle with area = π3? Answer: By above steps, area = π × r2 π3 = π × π2 by comparing, we get, radius, r = π Now put this value in formulae for circumference, cirucumference = 2 × π r = 2 × π π = 2 π2 Hence, we found the answer.
Area (A) of a Circle
A = π * radius2
Circumference (C) of a Circle
C = 2 * π * radius
To find the Circumference of a Circle given the area
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Solve for the radius of the circle
radius = (A / π)½
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Input the radius into the formula for the circumference and solve.
C = 2 * π * (A / π)½