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By using the other information supplied about the circle to calculate either its radius (from which its area can be calculated) or its area (if the circle is similar to another with a given area and some ratio between the two circle is given):

- If the diameter is given: radius = diameter ÷ 2
- If the circumference is given: radius = circumference ÷ 2π
- If the circle is similar to another circle which has a given area, and the length ratio is given; square the length ratio to get the area ratio and apply to the given area.

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The answer may depend on what other information you have about the circle.

Q: How do you find the area of a circle when the radius is unknown?

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The area of a circle is 153.86cm².find the radius of the circle

Radius = +sqrt(Area/pi)

the radius is from the center of the circle to the edge so that's how you find the radius.

11.3

Pi x radius(R) squared e.g radius of circle is 5cm A=3.14x5 squared Area is 78.5

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By dividing its diameter by 2 is equal to the radius of a circle and its area is pi*radius2

In a circle, the area of the circle is pi times the radius squared

The radius of a circle is the distance from the center to any point on the circle. The area is the space within the circle. The formula to find the area is πr2. r stands for the radius of the circle. If you want to find the radius, you can work backwards from the area or the circumference, which is the perimeter of the circle. The formula for circumference is 2πr.

Equation for the area circle = pi x radius squared If the area is 144pi, then you need to find the square root of 144, which is 12. Therefore, radius = 12

You find the area of a circle with pi times radius squared because the radius is half the circle so to find the full area you need to multiply it again.

The area of a circle is 153.86cm².find the radius of the circle

If yo have the area of the circle, the square is irrelevant. Radius = sqrt(Area/pi)

you take the radius and multiply it by itself. then you multiply the radius squared by 3.14 to get the area of a circle...

The answer depends on what information you are given.

Area of Circle = pi (radius)2 So , using this formula we can find the radius and also the diameter. Diameter = 2(radius)

Area of a circle = pi*radius2

Since the area of a circle is pi times radius squared, take the radius and square it. Then, multiply that by 3.14, or pi to get the area of the circle.