What is the best definition of primary source

The parking lot of a store has the shape shown. all angles are right angles. what is the area of the parking lot?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?