I've always held down shift while inserting my dimension to select the min or max of a radius or circle when dimensioning. The other way to do this is to right click on it and change it from center to min or max in properties. Ever since using 2008 I am having major issues with this. If I hold down shift while dimensioning it will not let me select anything. Also how come I cannot seem to find how to get the the properties of the dimension? Properties is not an option on the right mouse menu anymore. Please help!!! I've tried dragging the end of the dimension to the edge of the circle/radius but it only works some of the time. HELP!