I recently learned about the rectangular hyperbola. But I couldn't understand why is it called so?
I have seen similar questions on the internet saying that it is because the asymptotes of this hyperbola are perpendicular to each other.
But then, what is the relation between the term 'rectangle' and the perpendicularity of the two asymptotes??
[A rectangle has got right angles only at its corners, not at the intersections of its diagonals (and if it happens so, it is a square)]
The word rectangular is from latin angulus rectus = straight/upright angle. That is, the adjective rectangular does not mean "like a plane quadrangle with four right angles (aka. rectangles)".