Natural landscape with the reflection of a tree on the water surfaceNatural landscape with the reflection of a tree on the water surface
Water surface on the background of the sky and the sunWater surface on the background of the sky and the sun
The water surface of the sea in turquoise-blue colorsThe water surface of the sea in turquoise-blue colors
Pine trees and the sky reflected in the water surfacePine trees and the sky reflected in the water surface
В математике: граница, отделяющая геометрическое тело от внешнего пространства. Наружная сторона чего-н..