The value of which of these expressions is closest to e?

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

An energy plant is looking into putting in a system to remove harmful pollutants from its emissions going into earth's atmosphere. the cost of removing the pollutants can be modeled using the function c = 25000p/100 -p what is the vertical asymptote?

Two streets intersect at a 30- degree angle. at the intersection, the are four crosswalks formed that are the same length. what type of quadrilateral is formed by the crosswalks?