I'm assuming that the figure formed in this problem is a right angle. Thus, we need to use the Pythagorean theorem to get the distance or the hypotenuse.
Length = 20 meters Height = 16 meters
a² + b² = c²
(20m)² + (16m)² = c² 400m² + 256m² = c² 656m² = c² √656m² = √c² 25.61 m = c
