The length of a shadow of a building is 28m. the distance from the top of the building to the shadow is 38m. find the height of the building

It appears that the Pythagorean theorem can be applied to this problem
  (distance to shadow)² = (height of building)² + (length of shadow)²
  (38 m)² = (height of building)² + (28 m)²
  660 m² = (height of building)²
Then the height of the building is
  height of building = √660 m ≈ 25.7 m

A function is a set of ordered pairs in which no two different ordered pairs have the same x -coordinate. An equation that produces such a set of ordered pairs defines a function.