MathDB
Square and Rectangles

Source: 2014 amc 12b #21

February 20, 2014
geometryrectangletrigonometrysimilar trianglesPythagorean TheoremAMC

Problem Statement

In the figure, ABCDABCD is a square of side length 1. The rectangles JKHGJKHG and EBCFEBCF are congruent. What is BEBE? [asy] unitsize(150); pair A,B,C,D,E,F,G,H,J,K; A=(1,0); B=(0,0); C=(0,1); D=(1,1); draw(A--B--C--D--A);
E=(2-sqrt(3),0); F=(2-sqrt(3),1); draw(E--F);
G=(1,sqrt(3)/2); H=(2.5-sqrt(3),1); K=(2-sqrt(3),1-sqrt(3)/2); J=(0.5,0); draw(G--H--K--J--G);
label("AA",A,SE); label("BB",B,SW); label("CC",C,NW); label("DD",D,NE); label("EE",E,S); label("FF",F,N); label("GG",G,E); label("HH",H,N); label("KK",K,W); label("JJ",J,S); [/asy]
<spanclass=latexbold>(A)</span>12(62)<spanclass=latexbold>(B)</span>14<spanclass=latexbold>(C)</span>23<spanclass=latexbold>(D)</span>36<spanclass=latexbold>(E)</span>122 <span class='latex-bold'>(A) </span>\dfrac{1}{2}(\sqrt{6}-2)\qquad<span class='latex-bold'>(B) </span>\dfrac{1}{4}\qquad<span class='latex-bold'>(C) </span>2-\sqrt{3}\qquad<span class='latex-bold'>(D) </span>\dfrac{\sqrt{3}}{6}\qquad<span class='latex-bold'>(E) </span>1-\dfrac{\sqrt{2}}{2}