You can divide the diameter by two.
2 times pi times radius
A = Pi(r)2: A circle with a radius of 8 cm has an area of 201.06 square cm.
Take "pi" times the diameter of the circle. Pi = 3.14159 (ALWAYS) If circle has a diameter of 10cm, circumference 31.41cm If circle has a radius of 2inches, the circumference is 12.57 inches. (radius = 2, diameter = 4)
The formula is (pi x radius to the power of 2), so its 3.14 x 82.6= figure it out
To find the area of the circle pi*radius*squared and subtract the area of the figure inside
The radius of a circle is half of its diameter
When you try to figure out an area of a circle, you square the radius, then multiply it by pi to get the area of a circle. A radius square is radius x radius, or radius squared.
A congruent figure is identical to another figure. Example would be like a circle with the radius of 12 meters, then the congruent figure would have to be a circle with a 12 meter radius.
Pi times the radius of the circle squared = area And diameter is simply the radius x 2, since the radius is half the length of the circle.
You take out your ruler and measure it.
The area of any circle = pi*radius2
pi times radius squared. :)
Figure out the square root
Figure out its radius and multiply it by pi or 3.14.
If the figure is truly a circle, then the circumference is (Radius) x (2 pi) .
2 times pi times radius
The radius of a circle is from the middle to the edge, or half the diameter. The circumference is like the perimeter of the circle, and the formula is pi times the diameter.