The short answer is that all circles are geometrically similar. Ignoring the circle's position, you need a single number to characterize the circle.
The idea is that the diameter of the circle is always 2 times the radius, the circumference is equal to the radius times 2 times pi, and the area is calculated as pi times radius squared.
The radius of a circle is half of its diameter
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.
You take out your ruler and measure it.
The area of any circle = pi*radius2
The circumference is 42.83 becausecircumference = 2 x pi x r2 x 2.1415927 x 10 = 42.83Improved answer:Circumference of a circle = 2*pi*radius or pi*diameterCircumference = 20*pi = 62.83185307 units or 63 to the nearest unit.
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 can divide the diameter by two.
You take out your ruler and measure it.
The area of any circle = pi*radius2
Figure out the square root
pi times radius squared. :)
Figure out its radius and multiply it by pi or 3.14.
The circumference is 42.83 becausecircumference = 2 x pi x r2 x 2.1415927 x 10 = 42.83Improved answer:Circumference of a circle = 2*pi*radius or pi*diameterCircumference = 20*pi = 62.83185307 units or 63 to the nearest unit.
The circumference is equal to r2*pie or 38.5 inchesAnother answer:Circumference of a circle = 2*pi*radius or pi*diameterCircumference = 7*pi = 21.99114858 or 22.0 inches to one decimal place.