The Arc Tools are responsible for creating Arc Entities.
Find one of the Arc Tool icons 



on the Entity Toolbar (color coded blue) and click on the tool. The tool is now active and ready for use. This set of tools is part of a Flyout toolbar.
There are four different method that can be used to create an arc entity.
1.
Start-Middle-End Arc Tool: Arcs that pass through three chosen points (start point, middle point, and end point).
2.
Start-Center-End Arc Tool: Arcs drawn from a start point to an end point based on the location of a (circle's) center point.
3.
Start-Center-Angle Arc Tool: Arcs drawn from a start point to a point on a circle with a specific included angle based on the location of the (circle's) center point.
4.
Start-Center-Chord-Length Arc Tool: Arcs drawn from a start point to a point of specified chord length based on the location of the (circle's) center point.
5.
Start-End-Angle Arc Tool: Used to draw arcs from a star point, an end point, and an included angle.
Also See:
Arc Entity
Flyout Toolbar