Acute, all three sides are less than 90 degrees. Please state or re-state the less than 90 degrees in the Acute definition.
Geometry - Acute-angled triangles
Disregarding side lengths, and looking only at angle sizes, if the three
angles are all acute angles  then (surprise, surprise) it is called an
acute-angled triangle: 
* The sides may or may not be equal.
* For example, an equilateral triangle  is automatically acute-angled.
Previous | Next
Log in to save your progress and obtain a certificate in Alison’s free Geometry in Mathematics online course
Sign up to save your progress and obtain a certificate in Alison’s free Geometry in Mathematics online course
Please enter you email address and we will mail you a link to reset your password.