A clock is a circle with 12 equal sectors. A circle has 360 degrees so every time a minute hand number goes to another number it changes 30 degrees. After a full hour the time is 7 20 and it changes 360 degrees since the minute hand change over time was 12. 30x12=360.
Then it from 7 :20 and 8 00 the change 8 so is 30×8=240
