The purpose of this thread is to provide a link to posts that have geometric proofs. I shall gradually add to the list. From time to time I may move items about in the list to make it easier to find a particular item.
If you have requests, please reply in this thread and I’ll try to find (or create) what you want. Use the usual Help Me section if you need help with a particular problem. Normally I wouldn’t delete someone’s post, but I reserve the right to do so in this thread if it is becoming hard to keep track of new requests.
Two tangents to a circle from the same point are equal.
Angle properties of a circle.
Posts 6 and 7
The Inscribed Circle
Nine point circle
The Sine Rule
Intersecting chords theorem
If A, B, C and D are points on a circle , P is a point inside the circle where AB and CD intersect, then AP.BP = CP.DP.
If AB and CD intersect externally, the theorem still holds.
If two 2D shapes are congruent then the transformation that maps one onto the other is called an isometry.
The Regular Icosahedron
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei