Theangleatthecentreistwicetheangleatthe
circumference
Anglesinthesamesegement areequal
Theangleinasemicircleis90
degrees
Oppositeanglesinacyclicquadrilateraladdupto180
degrees
Theperpendicular fromthecentre tothechord
bisectsthechord
Theanglebetweenatangent andaradius
is90degrees
Tangentsfromapointoutsideacircleareequalinlength
Alternate segmenttheorem