2 . D
Put the given lengths into the figure:
The key is realizing that whatever base-altitude pair you take for the
same triangle, you’ll get the same area. One-half the product of PS and
RT is the same as one-half the product of PR and QS. Or, ignoring the one-
halfs, you can just say that the products are equal.
3 . E
The only information that’s in the question and not in the figure is that
and are parallel and that the area of ∆QRS is x. That and
are parallel tells you that triangles PRT and QRS are similar—they
have the same angles. Because the triangles are similar, the sides are
proportional. Because the ratio of PR to QR is the ratio of any pair of
corresponding sides will also be But that’s not the ratio of the areas.
