∆-ness does not depend on the point of observation. If you like, just stipulate that you always view the configuration from a point outside the affine span of the configuration but on the line perpendicular to the affine span and passing through the configuration’s barycenter. Then regular triangles, and only regular triangles, will project to regular triangles on your 2-dimensional display.
∆-ness does not depend on the point of observation. If you like, just stipulate that you always view the configuration from a point outside the affine span of the configuration but on the line perpendicular to the affine span and passing through the configuration’s barycenter. Then regular triangles, and only regular triangles, will project to regular triangles on your 2-dimensional display.