Acute Angle
/əˌkjuːt ˈæŋɡəl/noun
An angle measuring less than 90 degrees.
Did you know?The word acute entered English meaning physically sharp before developing medical, intellectual, and geometric meanings from the same Latin root.
Etymological Timeline
Proto-Indo-European
PIE
*ak-
“Sharp, pointed, or piercing”
Classical Latin
Latin
acutus
“Sharpened, pointed, or figuratively penetrating”
Ancient Greek
Greek
ankylos
“Bent or crooked; related to the root behind angle-like forms”
Latin
Latin
angulus
“A corner or angle”
14th Century
Middle English
acute
“Sharp-pointed; later applied to angles less than a right angle”
14th Century
Middle English
angle
“A corner or geometric figure formed by two lines”
Modern English
English
acute angle
“An angle measuring less than 90 degrees”