Preparation: Add four(4) Lines

1.Part-Editor: Click Geometry toolbar > Add Line:

To add the Line: Mouse Button Down - Drag - Mouse-Button-UP

2.Do again, again, and again to add four Lines as free Lines.

Make their start-Points near to each-other.

Add Coincident Constraint between Points

Note: Point must remain Red when you click Point

Add Coincident Constraint to the start-Points of two Lines.

1.Part-Editor: Click Constraints toolbar > Add Coincident Coincident

a.Part-Editor: Click Point

b.Part-Editor: Click Point

The two Points become coincident.

Merge-(two)start-Points of other two Lines.

2.Part-Editor: Click Geometry toolbar > Merge-Points

a.Part-Editor: Click Point

b.Part-Editor: Click Point

c.Click the graphic-area in a place with no other elements.

Delete Coincident Constraint

1.Part-Editor: Right-Click to deselect active commands

2.Part-Editor: SHIFT+CLICK the start-Point or end-Point or the Line in the graphic-area

All constraints that apply to the sketch-element(s) you click select show in the Selection-Window.

In the Selection-Window:

3.Right-click the Coincident-Constraint

4.Click Delete in the contextual-menu

Delete Merge-Points !

You cannot delete the Merge-Points. It is not an element. It removes a Point element.

To make a sketch-loop, the end-Points of each adjacent sketch-elements must be Merged-Points

If necessary, start the Part-Editor to add sketch-elements.

•Double-click the Part-Outline in the Mechanism-Editor

Use View Align if you prefer the X-axis of the new Part to be horizontal in the Part-Editor.

Add Line

STEP 1: Click Geometry toolbar > Add Line to the left of the graphic-area.

STEP 2: Drag the Line, approximately as shown

Add Arc

STEP 3: Click Geometry toolbar > Add Arc  to the left of the graphic-area.

To add an Arc, you must Drag two times:. See Add Arc video.

Drag 1: Add Start-Point and End-Point of the Arc

Mouse-button-down over an end-Point, move your mouse-pointer, mouse-button-up.

Mouse-button down with your mouse-pointer between the start-Point and end-Point of the Arc.

Drag 2: Locate the radius of the Arc

Drag again to approximate the radius of the Arc

Do Add Line and Add Arc commands again, two times more.

STEP 4: Add two more Lines and two more Arcs.

When you add the last sketch-element

STEP 5: Hover above the end-Point of the next-to-last sketch-element and the start-Point of the first sketch-element, to complete the sketch-loop.

If you miss a Point as you add the sketch-elements, CTRL+Z or use Geometry toolbar > Merge-Points to merge two Points into one Point.

The sketch is similar to the image to the left.