|Theorem: Angle is a semi circle is a right angle.|
Given : Angle AOB is in semi circle.
To prove: Angle ACB = 90o
Proof: Angle ACB = 1/2 angle AOB (angle subtended at the centre is twice angle at circumference)
Angle AOB = 180o (straight line) Hence ACB = 90o
Theorem: Angles in the same segment of a circle are equal.
Directions: Solve the following