An acute angle measures less than 90 degrees.
Understanding Acute Angles
In geometry, angles are classified based on their degree measure. An acute angle is specifically defined by how "sharp" or "narrow" it is. According to the definition, the measure of an acute angle is always smaller than that of a right angle.
What Defines an Acute Angle's Measure?
Based on standard geometric definitions, and as stated in the provided reference, the defining characteristic of an acute angle is its degree measure:
- The degree of an acute angle measures less than 90 degrees.
- This means its measure is also less than a right angle, which is precisely 90 degrees.
- The range of an acute angle degree is from 0 degrees (exclusive) up to, but not including, 90 degrees. So, an acute angle θ satisfies 0° < θ < 90°.
Examples of Acute Angles
The reference provides several clear examples of angle measures that fall within the definition of an acute angle. These include:
- 12°
- 35°
- 48°
- 65°
- 80°
- 89°
Any angle measuring between 0.000...1 degrees and 89.999...9 degrees would be considered acute.
Comparing Acute Angles
To better understand acute angles, it's helpful to compare them to other common angle types:
| Angle Type | Measure (Degrees) | Description |
|---|---|---|
| Acute Angle | > 0 and < 90 | Less than a right angle |
| Right Angle | = 90 | Forms a perfect square corner |
| Obtuse Angle | > 90 and < 180 | Greater than a right angle |
Therefore, the measure of an acute angle is anything in the range greater than 0 degrees and less than 90 degrees.
