How many right angles in circle?

Answer 1

The first answer here was "There are none." However, if you use Thales' Theorem, you will find that the number of right angles are actually close to infinite.

Thales' Theorem states that if points A, B and C are on the circumference of a circle, where the line AC is the diameter of the circle, then the resulting triangle will be a right triangle. As long as point B does not land on the same spots as points A or C, then no matter where point B is, you will have a right triangle. And wherever you have a right triangle, you'll always have a right angle.