Rectangle functions alter and obtain information about rectangles in a window's client area. Following are the rectangle functions:
| Function | Description |
| CopyRect | Makes a copy of an existing rectangle. |
| EqualRect | Finds out whether two rectangles are equal. |
| GetBoundsRect | Returns current accumulated bounding rectangle. |
| InflateRect | Expands or shrinks the specified rectangle. |
| IntersectRect | Finds the intersection of two rectangles. |
| OffsetRect | Moves a given rectangle. |
| PtInRect | Indicates whether a specified point lies within a given rectangle. |
| SetBoundsRect | Controls bounding-rectangle accumulation. |
| SetRectEmpty | Sets a rectangle to an empty rectangle. |
| SubtractRect | Creates a rectangle from the difference between two rectangles. |
| UnionRect | Stores the union of two rectangles. |
For detailed information about the rectangle functions, see the Microsoft Windows Programmer's Reference, Volume 2.