WOLFRAM|DEMONSTRATIONS PROJECT

Da Vinci's Construction of an Ellipse

α

0.685

b

0.375

c

0.68

As vertex

A

of triangle

ABC

slides along the horizontal axis, vertex

C

slides along the other axis, which does not have to be perpendicular. Vertex

B

then traces out the arc of an ellipse. There can be two solutions for

C

.