An angle whose measure is exactly 180 degrees is a straight angle.
It is an angle whose measure is between 90 and 180 degrees.
An angle measuring 90 to 180 degrees is an obtuse angle.
Obtuse
An angle whose degree measure is between 0 and 90 is an acute angle. An angle whose degree measure is between 90 and 180 is an obtuse angle. These are basic properties of geometry.
An obtuse angle
an angle whose measure is between 90 and 180
every 'obtuse' angle 135 degrees is the angle between 90 and 180. (91, 136, and 179 are a few others.)
straight angle or line.
An angle whose measure greater than 90 but less than 180 is an obtuse angle.
Given an angle A whose measure is in the range [0, 180] degrees, the supplementary angle to A is the angle B such that the measure of A + B = 180 degrees.
180-105 = 75