MathDB
Similar Triangles

Source: 2018 AMC 8 #20

November 20, 2018
AMC 8ratiogeometrysimilar triangles2018 AMC 8

Problem Statement

In ABC,\triangle ABC, a point EE is on AB\overline{AB} with AE=1AE=1 and EB=2.EB=2. Point DD is on AC\overline{AC} so that DEBC\overline{DE} \parallel \overline{BC} and point FF is on BC\overline{BC} so that EFAC.\overline{EF} \parallel \overline{AC}. What is the ratio of the area of CDEFCDEF to the area of ABC?\triangle ABC?
[asy] size(7cm); pair A,B,C,DD,EE,FF; A = (0,0); B = (3,0); C = (0.5,2.5); EE = (1,0); DD = intersectionpoint(A--C,EE--EE+(C-B)); FF = intersectionpoint(B--C,EE--EE+(C-A)); draw(A--B--C--A--DD--EE--FF,black+1bp); label("AA",A,S); label("BB",B,S); label("CC",C,N); label("DD",DD,W); label("EE",EE,S); label("FF",FF,NE); label("11",(A+EE)/2,S); label("22",(EE+B)/2,S); [/asy]
<spanclass=latexbold>(A)</span>49<spanclass=latexbold>(B)</span>12<spanclass=latexbold>(C)</span>59<spanclass=latexbold>(D)</span>35<spanclass=latexbold>(E)</span>23<span class='latex-bold'>(A) </span> \frac{4}{9} \qquad <span class='latex-bold'>(B) </span> \frac{1}{2} \qquad <span class='latex-bold'>(C) </span> \frac{5}{9} \qquad <span class='latex-bold'>(D) </span> \frac{3}{5} \qquad <span class='latex-bold'>(E) </span> \frac{2}{3}