UIBlock2D.CornerRadius

The Length configuration used to calculate a corner radius, applies to all four corners of the body, Border, and Shadow.

Remarks

CornerRadius.Percent is relative to half the minimum dimension (X or Y) of CalculatedSize. Mathematically speaking:
float calculatedCornerRadius = CornerRadius.Percent * 0.5f * Mathf.Min(CalculatedSize.X.Value, CalculatedSize.Y.Value)

Declaration

public ref Length CornerRadius { get; }