If perimeter is given in a square but length is not given what should we do

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)

Mr. t has been dating his girlfriend for one year nine months and six days how many hours has mr. t been in a relationship