Constructing an Ellipse (Concentric Circle Method)

Concentric circle method is  is used when the  major axis and minor axis of the ellipse iis given. This method is illustrated in figure 8 and  discussed below:

• With center C, draw two concentric circles with diameters equal to major and minor diameters of the ellipse.  Draw the major and minor diameters. 
• Construct a  line AB at any angle through C.  Mark points D and E where the line intersects the smaller circle.
• From points A and B, draw lines parallel to the minor diameter. Draw lines parallel to the major diameter through D & E. 
• The intersection of the lines from A and D is point F, and from B and E is point G.  Points F & G lies on the ellipse.
• Extend lines FD & BG and lines AF and GE to obtain two more points in the other quadrants.
• Repeat steps 2-6 to create more points in each quadrant and then draw a smooth curve through the points.
• With center C, draw two concentric circles with diameters equal to major and minor diameters of the ellipse.  Draw the major and minor diameters. 

Figure 8. Concentric circle method of drawing ellipse