you watch the clock or find a clock, in right angle there 90° or 3 o'clock, if you want to understand it, try to count the the minute from 12 to 3 in the clock, if you count it then you see the are there is 15 minutes, then the 90° divide the number of minute which is 15, the answer is 6°. and then the answer of the next question is acute angle it is because the hour hand of the clock travels in 1 minute, it means every 1minute there are 6°, and 6° is less than 90° that why it's acute angle.
