Look at the beginning and the end. It clearly says x ft = 30.48x cm
Since you have 8.5 ft, it says that 8.5 ft = 30.48*8.5 cm
Or are you suggesting that MarkFL or others just give you the answer? This is a math help site where we help students arrive at the answer on their own vs a site where they just supply you with the answer.
MarkFL derived the formula for you so that you can use it whenever you want, even if you forget it (since you now know how to derive it)