The following problem is modeled after a surveying question developed by a chinese mathematician during the tang dynasty in the seventh century c. e.
a building sits on the edge of a river. a man views the building from the opposite side of the river. he measures the angle of elevation with a handheld tool and finds the angle measure to be 45°. he moves 50 feet away from the river and remeasures the angle of elevation to be 30°. what is the height of the building? from his original location, how far away is the viewer from the top of the building? round to the nearest whole foot.