On a corner lot in any district within the triangular area determined as provided in this section, no wall or fence or other structure (except agricultural open wire fence) shall be erected to a height in excess of two feet; and no vehicle, object or any other structure of a height in excess of two feet shall be parked or placed; and no hedge, shrub or other growth shall be maintained at a height in excess of two feet, except those trees whose branches are trimmed away to a height of at least 10 feet above the curb level or pavement level where there is no curb shall be permitted. Such triangular area shall be determined by two points, one on each intersecting pavement line, each of which points is 50 feet from the intersection of such street lines.