a. the formula i = prt gives the amount of simple interest i earnest by principle p at an annual interest rate r over t years. solve this formula for p.
a. find p if r = 0.035, t =, and i = $420
c. what does the value p mean in your answer to part (b)?

to find s, the sum of the measures of the interior angles of a polygon with n sides, you can use the formula s = (n - 2) 180.
a. transform the formula to find the number of sides in terms of the interior angle sum. solve this equation for n.
b. complete the table at the right using your new formula.