Respuesta :

sqdancefan
The angle measures tell you the triangles are similar, so corresponding sides will have the same ratio.
  GX/BX = UH/NH
  GX = BX·UH/NH
  GX = 7·18/(3√11)
  GX = (42/11)√11

  GB/BX = UN/NH
  GB = BX·UN/NH
  GB = 7·15/(3√11)
  GB = (35/11)√11