Menu of inversive macros

These simple macros were written to avoid the need to repeat very basic constructions
when building pictures for inversive geometry.

Of course, Cabri has the built-in command inverse, which gives the inverse of a point in a circle.

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touching
Given a point A on a circle C and a point B not on C, draws the i-line through B touching C at A.
tangent
Given a point A on a circle C, draws the tangent to C at A.
circumcircle
Given three distinct points, draws the unique i-line through all of them.
invertcircle
Given circles C and D, draws the inverse of C in D - note the order!
invertline
Given a circle C and a line L, draws the inverse of L in C.
Warning these macros are not robust - if the construction requires a point on a circle,
you must choose a point on the circle. Otherwise you will get false results.

Main inversive page