An angle is the geometrical measure used to express the deviation between two lines or surfaces. Obtuse angles are observed wherever this deviation appears rather wide. Obtuse angle occur often along with the acute angle as these two supplement each other. Let us learn what an obtuse angle is how it is formed.

An obtuse angle is an angle whose angle measure is greater than 90º and less than 180º.In general if angle A is obtuse, then its degree measure is greater than 90º, but less than 180º.

Obtuse Angle
In the above diagram the angle BAC is greater than the right angle marked by a square sign.
m ∠BAC > 90º.

Indeed the obtuse angle is formed by adding an acute measure to the right angle.
Angle 2 which is obtuse makes a straight angle with the acute angle 1.
Thus 1 and 2 are supplementary angles. 
In general the supplement of an obtuse angle is acute.
The complement for an acute angle does not exist, as its measure is greater than 90º.