What is the upper limit in degrees for an obtuse angle?

An obtuse angle is defined as an angle that measures greater than 90 degrees but less than 180 degrees. Therefore, the upper limit for an obtuse angle is 180 degrees, as any angle that measures 180 degrees is classified as a straight angle, not an obtuse one. This understanding is essential in geometry, as it helps differentiate between the various categories of angles based on their measurements. The correct answer aligns perfectly with the definition of obtuse angles, affirming that while they begin at 90 degrees, their size can extend up to, but not including, 180 degrees.