#acute angle

• Sharp — Having a thinned and ground point or edge to easily cut, penetrate, or pierce; sharpened. In geometry, it describes an angle with an opening of less than 90 degrees, while in phonetics and acoustics, it refers to high-frequency, shrill, or piercing sounds or voices. As a neuter noun, it represents the action of abrasively processing a tool or a piercing audio signal.
• Acute-angled — Having all angles acute, meaning each angle measures strictly less than 90 degrees (or pi/2 radians); a term structurally used in geometry to classify triangles based on the size of their internal angles. Such a mathematical model implies the property that the orthocenter of the figure always lies inside its perimeter.