Thank you for writing.
The size of the panel can be changed like this:
sender, EventArgs e)
splitPanel1.SizeInfo.SizeMode = Telerik.WinControls.UI.Docking.SplitPanelSizeMode.Absolute;
More information can be found here: Building a layout of RadSplitContainers programmatically
The splitter width can be changed by setting the corresponding property:
radSplitContainer1.SplitterWidth = 20;
Please let me know if there is something else I can help you with.
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