How to Use Illustrator's Shape Builder Tool
Using the Adobe Illustrator CC Shape Builder tool, you can intuitively combine, edit, and fill shapes on your artboard. Follow these steps to create your own unique shape using the Shape Builder tool:
Create several overlapping shapes.
Select the shapes that you want to combine.
Select the Shape Builder tool and then click and drag across the selected shapes, as shown on the left in this figure.
The selected shapes are combined into one shape, as shown on the right in figure.
The Shape Builder tool also enables merging objects, breaking overlapping shapes, subtracting areas, and more.
Create another shape that overlaps your new combined shape.
Using the Selection tool, select both shapes.
Select the Shape Builder tool again.
Hold down the Alt (Windows) or Option (Mac) key and click and drag across the newly added shape, as shown in this figure.
It’s subtracted from the underlying shape.Use the Shape Builder tool to subtract from another shape.
Coloring fills and strokes is easier now, too. When you’re finished making your shape, you can use the Live Paint Bucket tool that is hidden in the Shape Builder tool to intuitively fill your shape with color.