Hello..I need your help...This issue that i have i think its a bit basic... :)when i make a frame.... and if i want at the face of the frame... or better.. on the side of the frame... lets imagine to put a steel round bar on the top of the frame.... after i choose to make a 3d sketch  i make a circle in the rop of the frame for make an extrusion later....  the inventor dont let me to make an extrusion... i dont understand what i am making wrong ... i know i can make a circle and an extrusion on a sketch... and later i make an assembly..  but that is too long for making a simple thing....thx