(1) LET OP and OQ be two lines at right angles, and let PQ move along them from O, so that OP always = OQ. Then PQ always > OQ or OP. You have full access to this article via your institution.

Two vectors close vectorA vector quantity has both direction and magnitude (size). are parallel if they have the same (or opposite) directions. Their magnitude can be different. In the image to the ...