first you need to find what the circumference would be if it was a circle, so measure how much it is from the middle of the straight line of the semi-circle to the top of the arc. Double this number (so 5cm would become 10cm) then type into a calculator π then the number ( so in this case π x 10.) Then halve the answer. :)
the fraction of the circle covered by the arc
To find the arc length, you also need to know the radius (or diameter) of the arc. The arc length is then found by finding the circumference of the full circle (2xPIxradius) and then dividing by 4 to find just one quarter of the circle (90 degrees).
length=n/360*2*pi*radius
angle of arc/ angle of circle (360°) = length of the arc/ total circumference (2 pi* radius) so you just have to find r then so: angle of arc/ angle of circle (360°) *2pi = length of the arc/ radius radius= ength of the arc/ angle of arc/ angle of circle (360°) *2pi not that hard ;)
Consist
the fraction of the circle covered by the arc
If you have only the arc length then you cannot find the diameter.
If you have the arc length:where:L is the arc length.R is the radius of the circle of which the sector is part.
Find the circumference of the whole circle and then multiply that length by 95/360.
To find the arc length, you also need to know the radius (or diameter) of the arc. The arc length is then found by finding the circumference of the full circle (2xPIxradius) and then dividing by 4 to find just one quarter of the circle (90 degrees).
It depends on what information you do have.
Use the information you have to find it. -- divide the length of the arc by the total circumference of the circle, or -- divide the central angle of the arc by 360 degrees (a full circle)
The length of an arc of a circle refers to the product of the central angle and the radius of the circle.
The length of the arc is r*theta where r is the radius and theta the angle subtended by the arc at the centre of the circle. If you do not know theta (or cannot derive it), you cannot find the length of the arc.
you will need to know the angle subtended by the arc; arc length = radius x angle in radians
length=n/360*2*pi*radius
(arc length / (radius * 2 * pi)) * 360 = angle