Answer : D. Obtuse; 120°
The figure shows ∠GOF drawn with a protractor.
From the given figure
Angle G = 15 degrees
Angle F = 135 degrees
The difference between angle F and angle G is the∠GOF
∠GOF = ∠F - ∠G = 135 - 15 = 120 degrees
When the angle is less than 90 degree then it is called as acute angle
When the angle is greater than 90 degree then it is called as obtuse angle
120 degree is greater than 90. so it is an obtuse angle