# Conics as envelopes: Ellipses and Hyperbolas

- Author:
- Juan Carlos Ponce Campuzano

Drag slider. Drag point A inside the circle.
The blue lines are the perpendicular bisectors of the points A and B.
How can you show that the envelope of the family of perpendicular bisectors is a hyperbola, when A is outside the circle, or an ellipse when A is inside?