how to keep proportions of this object
Hello,
I have created this object :

My goal is to have a circle. So at the top right of the screenshot I enter by example 45mm for width and height. But if I resize this object with the mouse it does not keep proportions as you can see in the screenshot.
I don't understand because at the red arrow you can see that width and height are linked (there is the linked symbol). So width and height should be the same number ?
How to keep proportions of this object by resizing it ?
