right triangleˌright ˈtriangle noun [countable] American English 
a triangle which has an angle of 90° SYN right-angled triangle British English
a triangle which has an angle of 90° SYN right-angled triangle British English- familiar
- familiarise
- familiarity
- familiarization
- familiarize
- familiarly
- family
- family circle
- family doctor
- family-friendly
- family man
- family name
- family planning
- Family Planning Association
- family practice
- family practitioner
- family room
- family tree
- family values
- famine
- famished
- famous
- Famous Five
- famously
- fan