you half the diamater to get the radius, then you square the radius. Then you times it by 3.14. Always. example. Diameter=4cm then radius =2cm squared=4cm 4x3.14=12.56
The perimeter of a full circle (circumference) is "pi" times the diameter. So the perimeter of a semi-circle will be half that; Perimeter = (pi/2) x (diameter).
To find the circumference of a circle, you have to multiply Pi and the Diameter. This means that to work out the answer you multiply Pi by 1.25. This equals 3.92699081, which rounded equals 3.93 (2dp) - the circumference of a circle with a 1.25 diameter.
It depends on what information you do have. If you know the radius, simply double it.
There are two kinds of ratios. One is the ratio of a circle, which is half the circle's diameter, (which is the length of the circle across), which can be used to find the circles area. (the ratio squared multiplied by pi). The other ratio is something that looks like this 1:2 which work similar to fractions. Such as, for every one ____ there are two ___.
The perimeter of a circle is called it circumference, "C". To calculate it, multiply its diameter by the constant, pi. Pi is roughly equal to 3.14159265. So, let's say you have a circle with a 10-foot diameter. Then C=10 x 3.14159265 = 31.42 (rounded off).
By dividing the diameter by 2 will give the circle's radius. Area of any circle = pi*radius squared.
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)
depends on the information given, but radius is half of the diameter.
The formula for the area of a circle is pi x radius2. The radius is half the diameter, and the diameter of an inscribed circle is the same as the length of a side of the square.The formula for the area of a circle is pi x radius2. The radius is half the diameter, and the diameter of an inscribed circle is the same as the length of a side of the square.The formula for the area of a circle is pi x radius2. The radius is half the diameter, and the diameter of an inscribed circle is the same as the length of a side of the square.The formula for the area of a circle is pi x radius2. The radius is half the diameter, and the diameter of an inscribed circle is the same as the length of a side of the square.
Given the diameter of the circle, multiply it by π (approx 3.14159).
C = pi*d Remember the circle eq'n To find 'd' we algebraically rearrange. to d = C/pi
area = pi*radius2Remember, to half the diameter to get the radius.Get the area of the outside circle, and the area of the inside circle, then take the inside area from the outside.I think it would be more helpful to you not to give you the answer. Work it out from this. If you are wondering what pi is, it is 3.14159
Assuming you know the radius or diameter...(Pi) x (radius) x (radius) or (1/4 Pi) x (diameter) x (diameter) will give you the area.
Area of a circle = pi*radius2 measured out in square unitsfor pi use this number 3.14159and remember the radius of a circle = half the diameter.----------------------------------------------------------------Thus a circle with a 10 inch diameter would have an area of:Radius = diamiter/2, which is 10/2= 53.14159 * (5*5) = 78.53975 square inches
The circumference of any circle divided by its diameter is always equal to pi. With this information we can work out various properties of the circle such as its circumference or its area.
The circumference of a circle is the distance around the circle. The formula is: C = pi * d (where pi = 3,1416 and d is the diameter) The diameter of a circle is the distance across the circle. The radius of a circle is one-half of the diameter The area of the circle is the amount of space contained within the circle. To calculate, the formula is: A = pi * r-squared (where pi = 3.1416 and r-squared is the radius multiplied by itself)
Area = pi*radius2 Area = 38.48451001 or 38.5 square meters to 1 d.p.