MathDB
Trapezoid and possible areas

Source: 2012 AMC12B #20

February 23, 2012
geometrytrapezoidparallelogramarea of a triangleHeron's formulaAMC

Problem Statement

A trapezoid has side lengths 3,5,7,3, 5, 7, and 1111. The sum of all the possible areas of the trapezoid can be written in the form of r1n1+r2n2+r3r_1 \sqrt{n_1} + r_2 \sqrt{n_2} + r_3, where r1,r2,r_1, r_2, and r3r_3 are rational numbers and n1n_1 and n2n_2 are positive integers not divisible by the square of a prime. What is the greatest integer less than or equal to r1+r2+r3+n1+n2?r_1 + r_2 + r_3 + n_1 + n_2?
<spanclass=latexbold>(A)</span> 57<spanclass=latexbold>(B)</span> 59<spanclass=latexbold>(C)</span> 61<spanclass=latexbold>(D)</span> 63<spanclass=latexbold>(E)</span> 65 <span class='latex-bold'>(A)</span>\ 57\qquad<span class='latex-bold'>(B)</span>\ 59\qquad<span class='latex-bold'>(C)</span>\ 61\qquad<span class='latex-bold'>(D)</span>\ 63\qquad<span class='latex-bold'>(E)</span>\ 65