I have no idea how or why, but in my inventor standard tool bar everything to the right of the ground shadow tool is inactive and i'm unable to select it or change the line tipe to construction or center
line while in 2d sketch mode.  I'm a begginer and i have no idea what setting could have caused
that or why, but is frustrating the everliving crap out of me!!!!!!!!!! please help

 
 Maybe you cad edit sketch and  change your linetype.
 
 Go to ->View->toolbars->Model Browser