hi, im new in altium, so i cant find a way to change default board size, i mean i have started my pcb, i need a 10X10 cm pcb board size, but altium by default have a board 4"x6" size, i have tried to set my pcb size when i start my pcb, but board size still 4"x6", so i have made my design in default size but i need change sizes, thanks
1) sketch you board outlines on any mechanical layer on mechanical 1 for example
2) select only the outlines
3) select "Define from selected objects" from "Designe --> Board shape" menu