CPM Homework Help : APCALC Problem 7-20

Right triangle, vertical leg is a lamppost, about half way between vertical leg & vertex opposite vertical leg, is a person standing between horizontal leg & hypotenuse, such that horizontal leg is divided into 2 parts, parts between person and right angle labeled, x, other part labeled, s. Patrick, who is $6$ feet tall, is walking way from a $10$ -foot tall lamppost. If he currently casts a shadow that is $12.5$ ft long, how far from the lamppost is he?

Hint:

Do you see two similar overlapping triangles? Recall that similar triangles have proportional sides. Set up a proportion and solve for $x$ .