From the Sketch section of the action bar, click 3 Point Rectangle.
In the 3D area:
Click to place the first corner point.
Click to place the second corner point along the same line.
A preview of a line appears that lets you specify the length of the
rectangle.
Click to place the third corner point.
A preview of a rectangle appears that lets you specify the width of the
rectangle.
Note:
The final rectangle has one parallel and two perpendicular constraints that define
the shape of it. If you sketch the first line as horizontal or vertical, the constraints
are applied accordingly.