# What does delta mean? [duplicate]

This question is an exact duplicate of: What does delta mean in terms of the curve table in the picture above?

## marked as duplicate by Vince, Fezter♦Apr 17 '18 at 0:30

This question was marked as an exact duplicate of an existing question.

• For context, where does your table come from? – PolyGeo Apr 16 '18 at 21:22
• Please edit previous closed questions instead of asking them again with fewer details. – Vince Apr 16 '18 at 21:28

## 1 Answer

Delta is the angle from the center of a theoretical circle on which each curve lies. For each curve, imagine two straight line segments of length Radius that converge at the center of the circle, and whose ends are at opposite ends of the arc curve. The angle where they converge will be delta. The imaginary straight line between them (right next to the actual arc curve) is the chord.

In this image, delta from your table is shown as theta at the center of the circle. Chord is show as rcrd*theta. The actual curve is shown as the section of the quarter-circle to the right of the chord segment. In the COGO toolbar, you using the curve calculator (circled in red in the image below), you can enter any two variables (for example, chord and angle/delta) to extract the remaining information, as shown. • great! but how would i input the given information (delta, chord length, radius) into a COGO tool in ArcMap 10.5? – Greg Jones Apr 17 '18 at 16:33
• See the updated comment. COGO calculator will give you all this information. – AlecZ Apr 17 '18 at 23:26