Why are circles so important to constructions?

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

Need ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?

According to a study done by de anza students, the height for asian adult males is normally distributed with an average of 66 inches and a standard deviation of 2.5 inches. suppose one asian adult male is randomly chosen. let x = height of the individual. a) give the distribution of x. x ~ b) find the probability that the person is between 64 and 69 inches. write the probability statement. what is the probability?