Circle theorems

Question 1

tangent theorems

Answer 1

two tangents from the same point are equal in length

a tangent meets a radius at 90°

the angle between a tangent and a chord is equal to any angle from that chord

Question 2

bow tie theorem

Answer 2

angles in the same segment are equal

Question 3

cyclic quadrilateral

Answer 3

opposite angles in a cyclic quadrilateral add up to 180°

Question 4

when there’s a diameter

Answer 4

an angle in a semi circle is 90°

Question 5

arrow

Answer 5

angle at the centre is double the angle at the circumference