Question

A surveyor standing 2,227 ft from the base of the World Trade Center in New York City measured a 31 degrees angle to the topmost point. To the nearest feet, how tall is the World Trade Center?

Answer 1

You can make a right triangle with the leg in between the building and the surveyor being 2,227 ft and the height of the building being the other leg (x).  To find x you can use the fact that tan(31)=x/2,227 which means x=tan(31)2,227.  Therefore x=1338.12 feet which means the building is 1338.12 feet tall.
I hope this helps.  let me know in the comments if anything is unclear.