GEOMETRY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site acute From the Latin acus for "needle" (which also forms the root for acid, acupuncture, and acumen). An acute angle is less than 90°. An acute triangle is one in which all three angles are acute. Compare with obtuse. Related category    • GEOMETRY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP