# Search Results for “Ellipse”

##### Ellipse Incenter Locus

What is the locus of the incenter of the triangle formed by the string in the "two pins and a piece of string" construction of an ellipse?##### Ellipse as locus of circle center

Take two overlapping circles. Examine the locus of the center of the circles tangential to both. It seems to be an ellipse with foci at the centers of the two circles. Prove it.##### Polar Point Ellipse

The polar point of a line in an ellipse is a common point to the chords defined by the common tangents through the points on the line. Play with it and the meaning will be clear! (Go to**Full Screen**if the green points won't drag)