Elliptic Arc
Create an elliptic arc to be used either as a building block for constructing geometry or as a wire.
On the Construct tab, in the Create arc
group, click the Elliptic arc icon.
Tip: Press A,1 to use the shortcut key.
Method 1: Centre point, radii, start angle, end angle

Centre point (C)  The centre of the ellipse on which the arc lies. 
Radius (RU)  The radius (half of the axis length) in the U axis direction of the ellipse on which the arc lies.  
Radius (RV)  The radius (half of the axis length) in the V axis direction of the ellipse on which the arc lies.  
Start angle (A0)  The angle, from the positive U axis direction where the arc begins.  
End angle (A1)  The angle, from the positive U axis direction where the arc ends 
Method 2: V major axis direction  Aperture centre, depth, aperture radius, eccentricity

Aperture centre (C)  The centre of the aperture formed by the elliptical arc section. 
Depth (D) 
The distance from the aperture centre point to the apex of the elliptical arc section. 

Aperture radius (R)  The radius of the aperture of the elliptic arc.  
Eccentricity  The eccentricity of the ellipse on which the elliptical arc section lies.
Note: The eccentricity must be less than 1 to specify a valid
ellipse.

Conditions for creating a valid elliptic arc:
Method 3: U major axis direction  Aperture centre, depth, aperture radius, eccentricity
Aperture centre (C)  The centre of the aperture formed by the elliptical arc section.  
Depth (D) 
The distance from the aperture centre point to the apex of the elliptical arc section. 

Aperture radius (R)  The radius of the aperture of the elliptic arc.  
Eccentricity  The eccentricity of the ellipse on which the elliptical arc section lies.
Note: The eccentricity must be less than 1 to specify a valid
ellipse.

Conditions for creating a valid elliptic arc: