Updated : 2021
How do you cut a circle in half in Adobe Illustrator tutorial.
There are many ways to cut a circle into halves in Adobe Illustrator. Probably the quickest with the recent releases of Illustrator are just using the pie slice features
You can cut the circle into two halves by using divide and pathfinder command and removing the excess.
You can also use the divide objects below command to cut a circle into half by using a single line. You can also use anchor point tool / pen tool to remove half of a circle in Adobe Illustrator. You can use the knife tool to cut a circle into two halves by using alt / option key. You can also use eraser tool and shift key to cut through a circle. The semi-circles can be moved apart and re-colored and scaled and rotated etc. This tutorial shows a number of methods to cut a circle in half in Adobe Illustrator
Select the ellipse tool in Adobe Illustrator toolbar
Draw circle by holding shift key down
View menu and smart guides ON
Draw a rectangle using the rectangle tool bigger than the circle
Shift the rectangle to cut the middle of circle (intersect will appear in the smart guide)
Pathfinder panel and divide
Object menu and ungroup
Delete remaining rectangle
As with many techniques in Adobe Illustrator, there are many ways to cut a circle in half. The above method uses the divide approach with a rectangle
Split into grid
Ellipse tool
Create a circle holding the shift down
Create a line using line segment tool top - down and bigger than the circle
Set line weight to 0 / stroke to no color
Select both paths using selection tool
Horizontal align center
Vertical align center
Keep line selected (de-select the circle)
Object menu
Path
Divide objects below
Circle has now been cut in half in Adobe Illustrator and can be moved apart by using the selection tool
You can also use the anchor point tool and pen tool to cut a circle in half (well, actually, just turn the path into a semi circle and that can then be duplicate and combined again as a circle)
Select circle
Click the pen tool
Go to the far left point and click with pen tool
Go to the anchor point tool
Click the top far left handle
Click the bottom left handle (of the circle)
Go to the eraser tool
Select the knife tool (beneath eraser tool)
Hover over top anchor point
hold alt / option
Draw through the top anchor
Through to the center
To the bottom anchor point
The alt / option key makes the knife a straight line knife
You can also cut the circle into two halves in Adobe Illustrator by using the scissor tool in the toolbar. A little less accurate (zoom in to see the top of the circle)
Select circle
Eraser tool in toolbar
Double click erase tool
Set size to 0
Go to the top anchor point
Hold shift
Click top anchor and draw scissor downwards
Release after bottom anchor point
You can now select either side of the circle. The semi circle can be re-colored
With the most recent versions, you can now simply create a circle (hold down the shift) and with the live circle selected go to the properties panel and click the first set of '...' to see more options and then go to the pie start angle field and enter 0 and then go to the pie end angle field and enter 180 and there you have your semi circle or cut circle.
It is live so if you want to use it as a normal circle, go to the object menu and shape and expand command. Not sure why the pie slice angles are not on the properties panel proper but instead require the additional action of clicking the more options. You could, of course, record this simple action and then apply this as an action to make it even quicker if you do this repeatedly. You can alway save the cut in half circle to your library so it is always accessible.
Of course, once you have your cut circle you can add it also to the symbols panel or perhaps use it with the repeat feature and go to the object menu and repeat and radial.
You can continue to work with the semi circle, perhaps add a shadow to the design etc Or perhaps use it with the blend tool