Calculates the radius of an arc when the width and height of the arc are given. The length of the arc and the angle subtended by the arc (not shown in figure) are also calculated. To draw the arc: 1)Swing arcs (using the calculated radius) below the width using as center the endpoints of the width thus creating the intersection point of the arcs. 2) Set the point of the compass at this intersection point (which now becomes the centerpoint of the arc) and swing an arc thru the endpoints of the width thus creating the arc. Take note that if the angle subtended by the arc (not shown in figure) is greater than 180 degrees then the arc length is greater than the arc length of a semi-circle. In this case, the centerpoint of the arc must be created above the width instead of below and the arc is drawn as before. Check out also the Calculator for Radius of an Arc #2 that calculates radius when the width and length of the arc are given. For a complete analysis of a circular arc please check out The Complete Circular Arc Calculator.