I have been stuck on this problem. Any help to get me started would be appreciated thanks.

A student in a stationary hot-air balloon is momentarily fixed at 1,325-ft elevation above a level piece of land. The pilot looks down( 60 degrees from the horizontal) and turns laterally 360 degrees.

a) how many acres are contained within the core generated by his line of sight?

b) how high would the balloon be if, when performing the same procedure an area 4 times greater is encompassed? (hint: 1 acre= 43,559.5 ft sq.)