Mathematics for IGCSE & O level - Circle Theorems (Section 2 - No. 10)
Which of the following statements about angles in circles are correct?
An angle at the center of a circle is twice the angle at the circumference.
Angles in the same segment of a circle are not equal.
The angle in a semi-circle is 90 degrees.
Opposite angles of a cyclic quadrilateral add up to 360 degrees.
解释
The angles at the center and in the semi-circle statements are correct.