Blunt Angle – What is it, examples and other types of angles

We explain what an obtuse angle is, its characteristics and examples from everyday life. Also, what other types of angles exist.

What is an obtuse angle?

In geometry, it is common to use the degree of opening or closing of an angle, measured in sexagesimal degrees or other units, to know what type of angle it is.

According to this logic, obtuse angles are called those with an amplitude greater than 90 ° sexagesimal but less than 180 ° sexagesimal. That is, they are wider than a right angle and less wide than a straight angle.

The obtuse angles are the widest known angle types, with the exception of the flat ones, and although they are rare, they can be found in geometric figures such as some scalene triangles (that is, obtuse triangles), rhombuses, trapezoids, hexagons and other irregular figures.

Characteristics of obtuse angles

The obtuse angles are characterized by the following:

• They have a great amplitude, which exceeds 90 ° sexagesimal (expressed in other units: 𝛑 / 2 radians, or 100^g centesimals) of the right angle.
• Its breadth, however, does not reach 180 ° straight angle.
• Its two sides are rays that meet at the vertex.

Examples of obtuse angles

The following are some examples of obtuse angles in everyday life:

• The angle it forms speedometer needle from your starting point (0 kmph) when you mark the car’s maximum speed.
• The angle it reaches a fan when it is opened to its fullest extent.
• The angle it draws the back of an armchair recliner or lounger chair when we lay down on it.
• The angle they form satellite dishes or parabolic with respect to the receiver at its vertex.
• Each one of the angles of a pentagon.

Angle types

In the same way that we identify obtuse angles, we can differentiate four other kinds of angles, such as:

• Null angles, which have an aperture of 0 ° (that is, they are non-existent).
• Right angles, which have an aperture exactly equal to 90 ° sexagesimal (and whose sides are perpendicular to each other).
• Acute angles, which have an aperture of less than 90 ° sexagesimal (that is, less open than right angles), but at the same time greater than 0 ° sexagesimal.
• Flat angles, which have an aperture of 180 ° sexagesimal (and whose sides are two consecutive lines that overlap at the vertex of the angle).