The answer to the question above is the third choice, "a shelf on a wall". The shelf is usually made of rectangular pieces of materials that are then connected to each other to form quadrilaterals. The sides of the shelf are planes.
A Surface is said to be plane, if we join any two points lying on the Surface, then line segment joining these two points Completely lies on the surface.
A shelf is a three dimensional Solid which we can call three dimensional plane, and A Wall is also a three dimensional Prism open from any one of the faces which we can call Surface or Plane.
Out of the four Options given ,the real world example of two planes intersecting are:
The surface area of the triangular prism that will be covered with insulation is equal to the area of the two triangular faces plus the two lateral rectangular faces
