Calculations at a circular segment or disk segment. A circular segment is formed by a circle and one of its chords. Enter two values of radius of the circle, the height of the segment, chord and its angle. Choose the number of decimal places, then click Calculate. Angles are calculated and displayed in degrees, here you can convert angle units.

Formulas:
Θ = 2 * arccos ( 1 - h / r )
h = r * ( 1 - cos(Θ/2) )
h = r - √ 4r² - s² / 2
s = 2 * √2 * r * h - h²
r = ( s²/4 + h² ) / (2h)
r = s / ( 2 * sin(Θ/2) )
l = r * Θ, (Θ in rad)
u = l + s
A = r * l / 2 - s * ( r - h ) / 2

Radius, height, lengths and perimeter have the same unit (e.g. meter), the area has this unit squared (e.g. square meter).

The circular segment is axially symmetrical about a straight line through the line of its height perpendicular to the chord. The chord of a circle is a straight line from one point on the circle to another. The circle segment is bounded by one of the two resulting arcs and this straight line. A chord divides the circle into two segments, if the chord does not pass through the center, into a smaller and a larger segment. When the chord is entered, the smaller circle segment is calculated.
If the chord passes through the center of the circle, then two semicircles are created. The part outside a circle segment is described by a circular corner or a circle tangent arrow. The extension of the circle segment towards the center of the circle is the circular sector. The three-dimensional extension of the circle segment is the spherical cap or, linearly extended into the third dimension, the cylindrical segment.
If you can only see part of a circle and can measure the height of this part and the length of the chord, i.e. the circle segment can be determined, then you can determine the radius of the circle.