You can use the Pythagorean theorem to answer this. The diagonal is the hypotenuse of the right triangle that is formed. So, your equation will look like (h is height):

We have to solve for h:


You can plug it into a calculator, and you get approximately 19.105. The answer closest to that is
B. So, that's your answer! Hope it helps. If anything doesn't make sense, hmu!
Answer:
In general, 5 and 3 quarters would be 5.75 :)
Remember, there are 4 quarters in $1.00
Part A:
y=mx+b
621=83(7)+b
Part B:
621=83(7)+b
621=581+b
621-581=b
b=40
Insurance cost is 40$