Merge multiple shapes into a single shape

You can create a single shape by combining multiple shapes. By combining rectangles, stars, regular polygons, etc. provided on the toolbar, you can draw more complex figures. You can combine shapes when they are overlapping.

The two methods of combining shapes are as follows:

Combination
The entire drawing areas of multiple shapes are combined into a single shape.
Intersection
Only the area where all of the shapes overlap with each other is extracted and converted into a single shape.

Figure 1. Original shape

Figure 2. Combine (left) and Intersection (right)

Restriction

Combine and intersection are only applicable to closed curve (polygons and other shapes with closed lines) among basic shapes. Arcs and Bezier curves are not closed. A spline curve is recognized as an item with a closed curve if you close the line with the "Close curve" feature.
When you select Combine or Intersection, the line color of the shape will change to black, and Line color pattern and Fill pattern will change to No fill.

Prerequisite

A mode is graphic mode.

Procedure

When combining multiple shapes

Select all the shapes you want to combine.
Select Edit - Synthetic Area - Combination.
Multiple shapes are combined into a spline curve.

When extracting only the part where multiple shapes intersect

Select all the shapes you want to combine.
Select Edit - Synthetic Area - Intersection.
Only the section where all of the shapes overlap with each other is extracted to form a combined spline curve.