In this course, we will be doing a lot of visual programming. A key to doing this is understanding the coordinate system. When we say
$morph('Rectangle').setPosition(pt(30, 30))
we're saying put the Rectangle at x = 30, y = 30. But what does that mean?
Each morph has a local coordinate system. x increases along the horizontal axis, and y increases going down the vertical axis. The coordinates of the four corners of the 740x415 blue rectangle are shown at the corners. Try clicking in the blue rectangle; the textbox in its center shows the value of the coordinate where the mouse is clicked