The formula for the area of a circle is:
area = pi x radius2.
The radius is half the diameter.
If you know the radius, the diameter is 2R If you know the circumference, the diameter is C/R If you know the area ,the diameter is 4A/pi (pi=3.142)
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.
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.
Measure the distance from top left corner of square (or top right) to the bottom right corner of square( or bottom left) to get the diameter of the circle. Then calculate the circumference from that figure.
If you're only given the length of the arc, then you can't. You also need to know the fraction of the circle that's in the sector. You can figure that out if you know the angle of the arc, or the radius or diameter of the circle. -- Diameter of the circle = 2 x (radius of the circle) -- Circumference of the circle = (pi) x (Diameter of the circle) -- (length of the arc)/(circumference of the circle) = the fraction of the whole circle that's in the sector or -- (degrees in the arc)/360 = the fraction of the whole circle that's in the sector -- Area of the circle = (pi) x (radius of the circle)2 -- Area of the sector = (Area of the circle) x (fraction of the whole circle that's in the sector)
If you know the radius, the diameter is 2R If you know the circumference, the diameter is C/R If you know the area ,the diameter is 4A/pi (pi=3.142)
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.
Assuming you are talking about a circle:* If you know the radius of the circle, multiply that by 2. * If you know the circumference of the circle, divide that by pi. * If you know nothing, you need to measure either the radius, the diameter, or the circumference.
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
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.
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.
Measure the distance from top left corner of square (or top right) to the bottom right corner of square( or bottom left) to get the diameter of the circle. Then calculate the circumference from that figure.
If you know the circle's Radius, the area is [ pi times r2 ]. If you know the circle's Diameter, the area is [ 1/4 pi D2 ].
D=Diameter, pi=3.14159... Area of circle = (D/2)2 * pi
To calculate this you will need the diameter of the circle. The formula is: diameter/2*pi If you don't know the diameter you can also use the area of the circle: Sqrt(Area/pi) = radius
If you're only given the length of the arc, then you can't. You also need to know the fraction of the circle that's in the sector. You can figure that out if you know the angle of the arc, or the radius or diameter of the circle. -- Diameter of the circle = 2 x (radius of the circle) -- Circumference of the circle = (pi) x (Diameter of the circle) -- (length of the arc)/(circumference of the circle) = the fraction of the whole circle that's in the sector or -- (degrees in the arc)/360 = the fraction of the whole circle that's in the sector -- Area of the circle = (pi) x (radius of the circle)2 -- Area of the sector = (Area of the circle) x (fraction of the whole circle that's in the sector)