## height & distance

Posted August 23rd, 2008 by alpha

A ladder rests against the wall at an angle alpha to the horizontal. Its foot is pulled away from the wall through a distance 'a', so it slides a distance 'b' down the wall making an angle beta with the horizontal. Show that -

a/b=(cos alpha-cos beta)/(sin beta-sin alpha)

I am unable to get the figure correctly.