A small, rectangular park has a perimeter of 560 feet and a diagonal measurement of 600 feet. What is its area, in square feet?	Choose the correct choice from the following options:
A) 172,800 B) 19,600 C) 20,000 D) 20,400 E) 20,800

Rationale: you can avoid a lot of work in this problem by recognizing that , with the info provided , the diagonal forms a triangle inside the rectangle with sides that have a 3 : 4 : 5 ratio . diagonal = 200 2 x + 2 y = 560 , or x + y = 280 a ^ 2 + b ^ 2 = c ^ 2 for each the sides of the triangle using the ratio 3 : 4 : 5 for sides , and knowing c = 600 , you can deduce the following a = 360 b = 480 360 x 480 = 172,800 a is the answer .
Answer: A