What is an obtuse angle?
The obtuse angle is that angle which measures more than 90°, but less than 180°.
See what an obtuse angle looks like:

How long is an obtuse angle?
The obtuse angle has no fixed measurement, as it varies according to its definition.
If θ is an obtuse angle then:
90°< θ < 180°
Examples of Obtuse Angles
Examples of obtuse angles are: 100°, 120°, 135°, 145°, 155°, 179°. Let’s see in the following drawing examples of this type of angle.
Geometric figures where the Obtuse angle is
The obtuse angle is in several figures, but where we see it is always in the obtuse triangle and in the rhombus.
Note the following geometric figures:

