In all zones which require a front yard, no obstruction of view in excess of three and one-half (3-1/2) feet in height shall be placed on any corner lot within a triangular area formed by the  curb lines and a line connecting them at points twenty (20) feet distant from the intersection of the  curb lines. Trees, pruned high enough to permit unobstructed vision to automobile drivers, are permitted within the above described triangular area. (PZSC § 03-11-017)(Ord. No. 96-07, Amended, 03/20/96)