1. The problem statement, all variables and given/known data Points A B and C lie on the circumference of a circle where $$A =(-3,2)\\B=(-1,6)\\C=(7,2)$$ Show that AC is the diameter of the circle. 2. Relevant equations 3. The attempt at a solution Would it be sufficient to show that the angle ABC is a right angle and therefore by the inscribed angle theorem that any angle subtended from a diameter is a right angle?