You're looking for the Adjust command, under Edit > Reshape > Adjust, also under the toolbar named "standard", or the shortcut ctrl- (ctrl minus) or Mac cmd-
You select ALL of the lines that you want to adjust/connect first (drag arrow selection box, or ctrl-click etc), then issue the adjust command ctrl- and finally click on an existing EDGE (mercedes cursor)...or draw a virtual line to adjust the elements to.
They will adjust to the longest length so if some of them are longer than others you may have undesirable results so make sure the ones you're adjusting aren't half as short as the longest ones you're trying to achieve
FREE wall Accessory framing and coverings bit.ly/BIMRithmWallAccessories
FREE Truss object. https://bit.ly/BIMRithmTrussV1 AC 24, Twinmotion current, Windows 11, Msi 10UG with rtx 3070, wacom intuos pro m, Wacom Cintiq Pro 16, razer Tartarus pro.