Can anyone help me on how to proof this:
If r and s are any points on a circle with center O and radius Ot, then Or is congruent to Os.
The only thing that I can think of is using Euclid's Postulate II.
Because we all know that the radius of a circle is constant. So any two radii, or any 3 radii, or any razillion radii of the same circle are congruent.
Why should Euclid's Postulate II be involved in proofing this?