conic.parallels([parallels]) The two

path.area(object) Returns the projected planar area (typically in square pixels) for the specified GeoJSON object

circle.radius([radius]) If radius is specified, sets the circle radius to the specified angle in degrees, and

d3.geoOrthographic() d3.geoOrthographicRaw

d3.geoTransverseMercator() d3.geoTransverseMercatorRaw