Circle facts and theorems
Circle Theorem 1
Move points A, B and C on the circumference. The pink lines are radii. What do you notice about the angles? Conjecture (idea for what the rule might be): Justification (using rules you already know):
Circle Theorem 2
Move points A, B and C on the circumference and look at how the angles change. Is it possible to make one of the angles = 90 degrees? Conjecture (idea for what the rule might be): Justification (using rules you already know):
Circle Theorem 3
Move any of the points on the circumference. What do you notice about the 2 angles shown? Conjecture (idea for what the rule might be): Justification (using rules you already know):
Circle Theorem 4
Move any of the points on the circumference. What do you notice about the angles? (hint: look at angles opposite each other) Conjecture (idea for what the rule might be): Justification (using rules you already know):
Circle Theorem 5
Move any of the points on the circumference. The blue line is a tangent to the circle. What do you notice about the angles? Conjecture (idea for what the rule might be): Justification (using rules you already know):