Use the circle with center through point tool to draw two circles with center A, one inside of the other, with about an inch between them. The inner circle will have radius AB and the outer circle will have radius AC.
Use the segment tool to draw a point on the larger circle and extend a diameter (DC) through A and B to C (you can use the arrow tool to adjust points so they fall on the line).
Use the point tool to label the second diameter point on the inner circle, E.
Use the perpendicular line tool to draw a perpendicular line to DC through A (click on DC then on A).
Use the intersection tool to mark the intersection points of the perpendicular line and the two circles. Click on the circumference of the inner circle then the perpendicular line, this will label points F and G, then click on the circumference of the outer circle then the perpendicular line to label points H and I.
Use the compass tool to measure the radius of the inner circle. Click on E and then A and then move the circle to the center E by clicking on E again. This will mark the distance of the radius above and below E. Repeat this process for the four points around the inner circle until you have four intersecting circles around the circumference.
Use the intersection tool to mark the intersection points of the new circles you constructed with the inner circle. Click on the inner circle then one of the constructed circles. Repeat until you have labeled the 8 intersection points. The inner circle now has a total of 12 points marked on its circumference.
Repeat steps 6 and 7 for the outer circle, using the compass tool to measure radius DA and place four circles on the circumference of the larger circle. Label those points with the intersection tool. You should have 12 points total marked on the outer circle.
Use the perpendicular line tool to create 4 perpendicular lines to the diameter DE through the outer circle. Click on DE and move the line until it intersects with each of the points on that outer circle that you labeled in step 8. Repeat until there are a total of 5 perpendicular lines including the original line you drew in step 4 (2 to the right and 2 to the left).
Use the parallel line tool to create 4 parallel lines to the diameter DE through the inner circle. Click on DE and move the line until it intersects with each of the points on the inner circle that you labeled in step 7. Repeat until there are a total of 5 parallel lines including the diameter DE (2 above and 2 below)
Use the intersection tool to mark the intersection of the parallel lines and the perpendicular lines. Click on the leftmost perpendicular line and the innermost parallel line closest to and above the diameter. Click on the same perpendicular line and the innermost parallel line closest to and below the diameter. Repeat on the rightmost perpendicular line. Then click on the perpendicular line between the one you just did and HI and the uppermost parallel line. Click on the same perpendicular line and then the lowermost parallel line. Repeat on the other side of the circle. You should have created 8 new intersection points.
The points you created in step 11 along with the points D, E, F, and G create an ellipse. Use the Freehand Shape tool to trace the ellipse between these 12 points. You have successfully constructed an ellipse!