How to apply different Round corners (Radius) in Sketch
Basic way to apply round corners
Select a rectangle and then from the right sidebar, move the slider or input the number for round corners.
You can see the round corners are applied to all 4 corners.
Different corners (Selecting specific corners to apply)
First select the rectangle. And double click on the path. Now you can edit each corner. Hold shift as you add or remove corners you want to edit.
On the sidebar input the amount you want. You can see the round corners get applied were you selected.
Faster way method. Type in your corners
You can get different corners you want by typing them in. Divide each value with a Semi-colon(;).
The order is from Top left, Top right, Bottom right, Bottom left. For this example, input ’24;0;24;0′.
What does the values mean?
In sketch the values are in pixels. The maximum value you can apply is half of the width or height. For a square, if you apply the maximum value you would get a circle. Not like in CSS you cannot apply percentage as values.