What is the angle between the minute and hour hands shown on the clock?
If the time shown is 6 o'clock then the angle between minutes and hours hand is 180∘.
Likewise, if it is 3 o'clock then the angle is 90∘.
So at 4 o'clock the angle will be greater than 90∘ and less than 180∘.
Hence, it is an obtuse angle.