In the rectangular coordinate system, are the points (a, b)

[Guest]

In the rectangular coordinate system, are the points (a, b) and (c, d) equidistant from the origin?

(1) a/b = c/d

(2) square root of a squared + square root of b squared= square root of c squared +square root of d squared

I don't understand the last piece of logic: If we know the proportion of a to b is the same as c to d and that |a| + |b| = |c| + |d|, then it must be the case that |a| = |c| and |b| = |d|. WHY IS THIS TRUE???

[StaceyKoprince]

See thread
http://www.manhattangmat.com/forums/quantitative-question-28-on-cat-1-t505.html