Count the number of \(3\times6\) rectangles in the \(50\times39\) grid above.
I'm lazy to draw new grids by the way.
Details and assumptions:
- Dimensions are expressed as width\(\times\)height. Thus a \(3\times6\) rectangle (that is, a rectangle of width 3 and height 6) is considered to be different to a \(6\times3\) (width 6 height 3) rectangle, in this case, you only want the \(3\times6\) rectangles, not the \(6\times3\) ones.