It is unlawful for any person to allow, or permit, or construct, or plant, or place any obstruction whatsoever, whether same be trees, shrubs, signs, fences or embankments which extend to a height in excess of two feet above the top of the curb or below seven and one-half feet above the top of the curb in the following areas: On all corner areas created by the intersection of two streets within the city in the triangular area formed as follows: From the point where the curb lines of the two intersecting streets meet, twenty-five feet along said curb line in each direction, with the third side of the triangle being a line across the corner bounded by the intersecting streets. (Ord. 1265-85 § 2, 1985).