At 3:00 the angle is 90 degrees since 3/12=1/4 of a circle or 360/4=90 degrees.
At 4:00 the angle is 120 degrees since 4/12=1/3 of a circle or 360/3=120 degrees.
At 3:30 the angle is 110 since the time is halfway between 3:00 and 4:00 or the average between these two angles or degrees.
I hope the above steps were helpful.
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