Right Angle in a Semicircle
Circle Properties: Right Angle in a Semicircle (Thales Theorem)
Circle Properties: Right Angle in a Semicircle (Thales Theorem)
This circle property is a special case of angle in centre = 2 times angle at circumference. This property occurs when AB is the diameter.
This circle property is a special case of angle in centre = 2 times angle at circumference. This property occurs when AB is the diameter.
Activity
Activity
Move points A and C around in the applet below, observe what happens to angle ACB.
Move points A and C around in the applet below, observe what happens to angle ACB.
Proof
Proof