Crows are able to look at a handful of four-sided shapes and correctly distinguish those that exhibit geometric regularity from those that don't, according to a provocative new study. It's the first ...

Parallel lines are straight lines which have the same direction and so never meet. Arrowheads show lines are parallel. A straight line that cuts a pair of parallel lines is called an intersecting ...

In flat space, two parallel lines never meet, however, they appear to meet at very distances for the same reason due to which objects appear smaller when they are at a distance than when they are ...