Locus of Incircles

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If we look at the usual pin and string ellipse construction and take the locus of the incenters of the triangle formed by the string, we see it also is an ellipse.

Expressions

Name Input
Locus 1 Eq Derive Input Maple Input MathML Input Mathematica Input Maxima Input Mupad Input TI-Nspire Input text Input Image
Locus 2 Eq Derive Input Maple Input MathML Input Mathematica Input Maxima Input Mupad Input TI-Nspire Input text Input Image