Respuesta :

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