Finding the Radius or Diameter of an Arc

The diameter or radius for an arc can be easily found when given two of the following* as inputs:


Arc Illustration


Example1:  Find the radius of an arc given a Segment Height (Rise) of 2m and a Chord Length (Run) of 6m
Input
[clr] [clr]
6 [m]
[ Run ]
2 [m] [Rise]
[Conv] [Radius]
Display
0

   6m
Run
    6m
Rise
    2m
Radius
    3.25m

Example2:  Find the diameter of an arc given a Segment Height (Rise) of 6ft 2in and a 120° arc angle.
Input
[clr] [clr]
6 [Feet] 2 [Inches]
[ Rise ]
120 [Arc]
[Circle]
Display
0

   6ft 2in
Run
    6ft 2in
Arc Angle
    120.00°
Diameter
    24ft 8in

Example3:  Find the radius and diameter of an arc given a Chord Length (Run) of 36 inch and a 30° arc angle.
Input
[clr] [clr]
36 [Inches] [Run]
30 [Arc]
[Conv] [Radius]
[Circle]
Display
0
Run
   36in
Arc Angle
    30.00°
Radius
    69- 9/16in
Diameter
   139- 1/16in



Note that the [Arc] function can be used to calculate the length of each stud required to frame an arch.

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