How to Apply Corners:

To apply corners first enter widget mode and click the pencil icon of the widget. Next, click style. Finally click on the corners tool.

See Also:

Here is how to apply corners:

Step 1: Login to your EXAI account and open the website in widget mode 
Step 3: Click the style tab (A). 
Step 4: Click corners icon (B).
Step 5: Choose the corners (C) and type in the length (D)or use the slider.
Note: You can also adjust the corners from widget mode under the style tab.

You can make the corners of any layer or element rounded so that they can give a more attractive look. You can do this very easily and give a radius to the corners up to 50%. You can also make selected corners rounded and apply the corner property to those only.  
Note: You can make an image circular by adjusting the corners under style