Technical Graphics - Plane Figures - The Ellipse

Rectangle Construction Method

Step 1 : Draw your Major and Minor Axes. (green lines)
Step 2 : Now draw a rectangle around the Major and Minor Axes as shown. ( light blue lines)
Step 3 : Divide both halves of the Major Axis into an equal number of parts. Here we have used four parts. Now divide the each half of the edges of the light blue rectangle, corresponding to the Minor Axis, into the same number of parts. Label all of these points as you see in the diagram. (blue dots)
Step 4 : Next you have to join the ends of the Minor Axis to the divisions on the edge on the rectangle. Then from the opposite end of the Minor Axis draw lines through the divisions on the Major Axis until they intersect the first set of lines you have drawn. Here we have only shown half of the lines for clarity. (red lines)
Step 5 : Here you can see the completed set up.
Step 6 : Join up all of the points of intersection and the points labeled '0' to form your Ellipse. (black lines)
And now you are finished. You can draw an Ellipse in any direction with this method, but remember you must know the length of the Major Axis and the Minor Axis, or be able to find them out.