Take the radius (half of the diameter), square it, and multiply it by pi.
A = (pi) r2
A = (pi) (D/2)2
A semicircle is 1/2 of a circle. Find the area with the diameter you are given as if you had a whole circle, then divide that answer by 2 to get the area of the semicircle.
Area of Circle = pi (radius)2 So , using this formula we can find the radius and also the diameter. Diameter = 2(radius)
That depends on what you know. If you know the radius of the circle, double it to get the diameter. If you know the circumference of the circle, divide it by π to get the diameter. If you know the area of the circle, find its square root and divide the result by π to get the radius then multiply by 2 to get the diameter.
radius = diameter/2 area of a circle in square units = pi*radius2
You can measure it. Otherwise, you certainly have to know SOMETHING about the circle to calculate the radius, usually the diameter, the circumference, or the area. If you don't know anything at all about a circle, you can't find out the radius, either.
To find the diameter of a circle, you will either need to know the area or its circumference. If you know the area: diameter = 2 x squareroot(area / Pi) If you know the circumference diameter = circumference / Pi
A semicircle is 1/2 of a circle. Find the area with the diameter you are given as if you had a whole circle, then divide that answer by 2 to get the area of the semicircle.
In order to find the diameter of a circle if you have the area is to rearrange the formula for the area of a circle to put diameter as the unknown, like so: PIE*d = Area of a Circle d = (Area of a Circle) / PIE Therefore if the area of your circle is 40cm, 40/PIE = 12.73cm and that's the diameter.
Area of Circle = pi (radius)2 So , using this formula we can find the radius and also the diameter. Diameter = 2(radius)
That depends on what you know. If you know the radius of the circle, double it to get the diameter. If you know the circumference of the circle, divide it by π to get the diameter. If you know the area of the circle, find its square root and divide the result by π to get the radius then multiply by 2 to get the diameter.
radius = diameter/2 area of a circle in square units = pi*radius2
I do not know about a circle with an area of 100 nmm3.A circle with an area of 100 mm2 has a diameter of 11.28 mm.
You can measure it. Otherwise, you certainly have to know SOMETHING about the circle to calculate the radius, usually the diameter, the circumference, or the area. If you don't know anything at all about a circle, you can't find out the radius, either.
The formula for the area of a circle is: area = pi x radius2. The radius is half the diameter.
If you have the circumference- You have to divide the circumference by 2*Pi If you know the diameter the radius is simply half the diameter. If you know the area of a circle, the radius can be found using the formula : R = √A/π where: A is the area of the circle and π is Pi, approximately 3.142.
OK, SO to find the area of a circle, you find the radius (half of the diameter), and fit it into the equation πr2=A where r equals radius and A = area. The perimeter of a circle is π multiplied by the diameter. π is ≈ 3.1415296.
Divide the known circumference by pi to find the diameter of the circle.