7pi/4 on the unit circle

Do u just plot the numbers on the graph like (1,

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle