The location and boundaries of districts are and shall be as shown on the Zone Map; provided that, where the designation on the Map indicates a district boundary approximately on a street or alley line or on a lot line, the centerline of such street approximately on a street or alley line or on a lot line, the centerline of such street or alley, or such lot line, shall be construed to be the boundary.
Where uncertainty exists as to the exact boundaries of any district as shown on the Map the following rules shall apply:
(a) In unsubdivided areas, or where a district boundary subdivides a lot, the exact location of the boundary line shall be determined by use of the scale of the Map.
(b) In the case of further uncertainty, the Board of Zoning Appeals shall interpret the intent of the Map as to the location of the boundary in question.