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Cutting triangle to form a pentagon!

Source:

November 21, 2005
geometry

Problem Statement

A pentagon is formed by cutting a triangular corner from a rectangular piece of paper. The five sides of the pentagon have lengths 13,19,20,2513,19,20,25 and 3131, although this is not necessarily their order around the pentagon. The area of the pentagon is
<spanclass=latexbold>(A)</span> 459<spanclass=latexbold>(B)</span> 600<spanclass=latexbold>(C)</span> 680<spanclass=latexbold>(D)</span> 720<spanclass=latexbold>(E)</span> 745<span class='latex-bold'>(A)</span>\ 459 \qquad <span class='latex-bold'>(B)</span>\ 600 \qquad <span class='latex-bold'>(C)</span>\ 680 \qquad <span class='latex-bold'>(D)</span>\ 720\qquad <span class='latex-bold'>(E)</span>\ 745