Definition

1. Noun:
   • A geometric angle measuring less than 90 degrees but more than 0 degrees: An "acute angle" is a specific type of angle formed by two lines or rays that meet at a point (vertex), where the opening between them is narrower than a right angle (90°) but wider than zero degrees.

Usage

• The term "acute angle" is used primarily in geometry, mathematics, engineering, and design to describe and classify angles.
• It is a countable noun. You can have one acute angle or multiple acute angles in a shape.
• It is typically used with the verb "to be" (e.g., ) or "to have" (e.g., ).

Examples

• Noun:
  • An equilateral triangle has three equal acute angles, each measuring 60 degrees.
  • When the hands of a clock show 2:00, they form an acute angle.
  • The roof was designed with a steep, acute angle to shed snow easily.

Advanced Usage

• "Acute-angled" (Adjective): Describing a shape that contains acute angles.
  • An acute-angled triangle is a triangle where all three interior angles are less than 90 degrees.
• In trigonometry, the functions (sine, cosine, tangent) for acute angles are defined using right triangles.

Variants and Related Words

• Angle (n): The space between two intersecting lines or surfaces at or close to the point where they meet.
• Right angle (n): An angle of exactly 90 degrees.
• Obtuse angle (n): An angle greater than 90 degrees but less than 180 degrees.
• Reflex angle (n): An angle greater than 180 degrees but less than 360 degrees.

Synonyms

• Sharp angle: (Informal, less precise) Can sometimes be used to describe an acute angle, emphasizing its narrow, pointed nature.

Antonyms

• Obtuse angle: An angle greater than 90 degrees.
• Right angle: An angle of exactly 90 degrees.

Noun

1. an angle less than 90 degrees but more than 0 degrees