MathDB
Index Cards :D

Source: 2022 AMC 10A #10

November 11, 2022
AMC 10AMC2022 AMC 10a2022 AMCgeometryarea

Problem Statement

Daniel finds a rectangular index card and measures its diagonal to be 8 centimeters. Daniel then cuts out equal squares of side 1 cm at two opposite corners of the index card and measures the distance between the two closest vertices of these squares to be 424\sqrt{2} centimeters, as shown below. What is the area of the original index card?
[asy] unitsize(0.6 cm);
pair A, B, C, D, E, F, G, H; real x, y; x = 9; y = 5;
A = (0,y); B = (x - 1,y); C = (x - 1,y - 1); D = (x,y - 1); E = (x,0); F = (1,0); G = (1,1); H = (0,1);
draw(A--B--C--D--E--F--G--H--cycle); draw(interp(C,G,0.03)--interp(C,G,0.97), dashed, Arrows(6)); draw(interp(A,E,0.03)--interp(A,E,0.97), dashed, Arrows(6));
label("11", (B + C)/2, W); label("11", (C + D)/2, S); label("88", interp(A,E,0.3), NE); label("424 \sqrt{2}", interp(G,C,0.2), SE); [/asy]
<spanclass=latexbold>(A)</span>14<spanclass=latexbold>(B)</span>102<spanclass=latexbold>(C)</span>16<spanclass=latexbold>(D)</span>122<spanclass=latexbold>(E)</span>18<span class='latex-bold'>(A) </span>14\qquad<span class='latex-bold'>(B) </span>10\sqrt{2}\qquad<span class='latex-bold'>(C) </span>16\qquad<span class='latex-bold'>(D) </span>12\sqrt{2}\qquad<span class='latex-bold'>(E) </span>18