Zenithal Gnomonic Equatorial Projection
 Lines of Latitude •Equator •Latitudes Lines of Longitude •Prime Meridian •Longitudes Relationships Facts on Earth Zenithal Projections •Gnomonic Polar •Gnomonic Equatorial •Stereographic Polar •Stereographic Equatorial •Orthographic Polar •Orthographic Equatorial Simple Conic Projection Cylindrical Equal-area Projection References Figure A Figure B Figure C For the equatorial case of the Gnomonic projection, the source of light is situated at the centre of the globe, like in all other gnomonic projections. But, unlike that of the polar case, the plane of projection (dark purple in Figure A) touches the globe at the equator (green line). When projected, all great circles are again represented as straight lines in the projection plane. This is depicted in Figure A where the green line on the plane is the projected equator and the light purple lines represent straight and parallel meridians. Unlike the equator, other parallels are curves conves to the equator. Note the red line on the projection plane in Figure A is where the projected parallel intersects with the particular light puple meridian. Refering to Figure B, the mathematical calculations for the intersections of parallels with the meridians can be logically deduced. With the equator running from AB and touching the earth tangentially at point A, the central meridian becomes projected at the same point from the light ray AC. Because the light ray goes through the centre and touches the tangential point, it satisfies both conditions which leads to a perpendicular intersection with the equator. As such,