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Area of circle given circumference
All Geometry math games
Area of triangle
Identify side of triangle given area
Area of quadrilateral
Identify side of quadrilateral given area
Area of circle given radius
Area of circle given circumference
Circumference of a circle given radius
Radius of a circle given circumference
Volume of sphere, cone, cylinder
Volume of cuboid
What is the area of the circle, if the circumference is
18π
?
9
81π
81
9π
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Hint
Can you answer 10 correctly?
The area of the circle is
?
Area
=
π
radius
2
The area of a circle is the amount of space that is contained within the 2-dimensional object. It is calculated by the equation
πr
2
π
(spelled pi, but pronounced like a slice of pie) is the constant value of 3.14159...
r
equals the length of the radius of the circle, which is the length from the center of the circle to any edge
For example, if the radius of a circle is 4 inches
Calculate the square of the radius by multiplying 4 inches by 4 inches, or 16 sq. inches
Multiply that by π, which results in 16π, or approximately 50.24 sq. inches
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