How do you get rid of an exponent on a variable?

Aladder that is 30 ft long needs to reach 27 ft up a building. what should the angle of the vertical be?

Ineed with math stuff it involves graphs

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park is the cost of admission proportional to the amount of people entering the amusement park? explain.