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2020 Individual #6

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April 30, 2022
2020 Individualgeometry

Problem Statement

The top vertex of this equilateral triangle is folded over the shown dashed line. Which of the 5 points will the vertex lie closest to after this fold? [asy] size(110); draw((0,0)--(1,0)--(0.5,sqrt(3)/2)--cycle); dot((0.5,sqrt(3)/2)); pair A_1=(0,0);label("A1A_1",A_1,S);dot(A_1); pair A_2=(0.25,0);label("A2A_2",A_2,S);dot(A_2); pair A_3=(0.5,0);label("A3A_3",A_3,S);dot(A_3); pair A_4=(0.75,0);label("A4A_4",A_4,S);dot(A_4); pair A_5=(1,0);label("A5A_5",A_5,S);dot(A_5); draw((0.23,0.38)--(0.86,0.22),dashed); [/asy] <spanclass=latexbold>(A)</span>A1<spanclass=latexbold>(B)</span>A2<spanclass=latexbold>(C)</span>A3<spanclass=latexbold>(D)</span>A4<spanclass=latexbold>(E)</span>A5<span class='latex-bold'>(A) </span>A_1\qquad<span class='latex-bold'>(B) </span>A_2\qquad<span class='latex-bold'>(C) </span>A_3\qquad<span class='latex-bold'>(D) </span>A_4\qquad<span class='latex-bold'>(E) </span>A_5