The Acute Angle is an angle whose measurement is greater than 0° and less than 90°.
Note this definition in the figure below:
The acute angle is a very common angle, we see it in different geometric figures such as: triangle, rhombus, circumference, and so on.
Note different examples of acute angles.
In this figure, note how angles depending on their size have different «openings»; in addition, they could also be considered as examples of acute angles: 1°, 15°, 89.9999° and all those angles that are within: 0° < α < 90°
Measurement of an Acute Angle
Measuring an acute angle is a simple task, for which a protractor must be used. Then, the 90° angle is located and the angles below it will be acute angles, except for the 0° angle, by definition.
See how it is done:
Here an acute angle equal to 60° has been measured, which is the characteristic angle of an equilateral triangle.
Another geometric figure where we see two acute angles is in the isosceles triangle, see the following graph:
The angles «α» are acute; but, «θ» can be acute, right or obtuse.