Frame
Support angles
How far back the brace reaches along each piece.
Boards & sheets
Click a piece to select it. The arrows in its middle move the whole thing and the rings turn it — that is how you drop a beam onto two posts. CLICK an end handle to pin that end instead: the arrows jump to the other end and the piece swings about the joint, so you can aim it without tearing it off what it is fixed to. Click the body again to let go. Shift-click adds pieces; Ctrl+C, Ctrl+V and Ctrl+D copy them.