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Well...a "sector" is part of a circle...which has a radius. But in order to calculate the radius, you'd need both the total area of the circle, and the central angle of the sector (or enough information to get the central angle).

Let's say you're looking at a clock (and let's assume both the minute hand and the hour hand are the same length, and extend from the center all the way to the edge of the clock). Assuming this, the length of both hands would be the radius, as they are segments whose endpoints are the center of the circle, and a point on the circle.

If you put the hands of the clock at the 12 and 3, you've just created a sector that is 1/4 of the entire area. The angle created by these hands would have a vertex that is the center of the circle...and this would be the "central angle"...and it would have a measure of 1/4 of 360...which is 90.

But...while you can say what "fraction" of the circle is encompassed by the sector, you can't do any calculations until you have somewhere to start from. Let's say in the above example, you knew that the entire area of the circle was 64pi. The radius of that circle would be the square root of 64=8. This would, obviously be the radius of the sector as well...but since our "central angle" was 90...the AREA of the sector is 90/360 (or 1/4) of the total area. Since our initial area was 64pi...the area of the sector would be 16pi.

But if all you want is a simple formula, the radius of a circle (and by extension the sector), given the area of the sector (s) and the measure of the central angle (c) would be the square root of [(360*s)/(c*pi)]

Q: How do you calculate the radius of a sector?

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the area of a sector = (angle)/360 x PI x radius x radius pi r squared

Not enough information is given to work out the radius of the circle as for instance what is the length of sector's arc in degrees

Double the Radius to Calculate the Diameter.

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A sector is a part of a circle which looks the same shape as a piece of a circular pie. You probably remember that Pi charts look like a circular cake cut into portions. We can calculate the area of the sector of a circle if we know the angle between the two straight sides and the radius of the circle. Now the area of a complete circle is Pi x square of radius, If the radius is 12 cm then the circle's area will be Pi x square of 12 square centimetres. But that is for the full circle. If the sector's angle is 60 degrees, that would mean that the area of the sector would be 60 degrees/360 degrees which equals 1/6; so finally, the area of the sector is (Pi x 12 squared) divided by 6 = 75.398 sq cm )correct to 4 decimal places).

Related questions

The area of the sector is: 221.2 cm2

if a circle has a radius of 12cm and a sector defined by a 120 degree arc what is the area of the sector

the area of a sector = (angle)/360 x PI x radius x radius pi r squared

Not enough information is given to work out the radius of the circle as for instance what is the length of sector's arc in degrees

The radius of the sector with an angle of 27 degrees and arc of 12cm is: 25.46 cm

If a sector has an angle of 118.7 and an arc length of 58.95 mm its radius is: 28.45 mm

The arc length of a sector that is 125 degrees and has a radius of 20 inches is: 43.63 inches.

Find the area of the shaded sector. radius of 3 ...A+ = 7.07

To calculate the arc length of a sector: calculate the circumference length, using (pi * diameter), then multiply by (sector angle / 360 degrees) so : (pi * diameter) * (sector angle / 360) = arc length

Double the Radius to Calculate the Diameter.

It depends on what information you have: the radius and the area of the sector or the length of the arc.

how to calculate the elbow radius or elbow length