https://forums.autodesk.com/t5/inventor-forum/dimensions-needed/m-p/5741553#M366856 <P>First: please always say what version of Inventor you're using. &nbsp;I discovered that the file you posted is Inventor 2014 format, but it would be much easier for anyone considering offering help to know right away what version they should work with.</P> <P>&nbsp;</P> <P>As&nbsp;@Anonymous&nbsp;pointed out, the unconstrained parts are the endpoints of your construction lines (mathematically speaking, they are actually line segments). &nbsp;Inventor 2014 is just waiting for you to ask with the <STRONG>Show All Degrees of Freedom</STRONG> button as illustrated below:</P> <P>&nbsp;</P> <P><IMG src="https://forums.autodesk.com/t5/image/serverpage/image-id/180438i0DC55DF01CE6C521/image-size/original?v=mpbl-1&amp;px=-1" border="0" alt="Sketch DOF.png" title="Sketch DOF.png" /><BR /><BR />Sam B<BR /><BR />Inventor Professional 2016 Update 2<BR />Vault Basic 2016<BR />Windows 7 Enterprise 64-bit, SP1</P> Mon, 27 Jul 2015 11:09:15 GMT SBix26 2015-07-27T11:09:15Z