MathDB
Area of Triangle

Source:

January 4, 2009
geometryrectangleratio

Problem Statement

In rectangle ABCD ABCD, AB\equal{}5 and BC\equal{}3. Points F F and G G are on CD \overline{CD} so that DF\equal{}1 and GC\equal{}2. Lines AF AF and BG BG intersect at E E. Find the area of AEB \triangle{AEB}. [asy]unitsize(6mm); defaultpen(linewidth(.8pt)+fontsize(8pt));
pair A=(0,0), B=(5,0), C=(5,3), D=(0,3), F=(1,3), G=(3,3); pair E=extension(A,F,B,G); draw(A--B--C--D--A--E--B);
label("AA",A,SW); label("BB",B,SE); label("CC",C,NE); label("DD",D,NW); label("EE",E,N); label("FF",F,SE); label("GG",G,SW); label("BB",B,SE);
label("1",midpoint(D--F),N); label("2",midpoint(G--C),N); label("3",midpoint(B--C),E); label("3",midpoint(A--D),W); label("5",midpoint(A--B),S);[/asy]<spanclass=latexbold>(A)</span> 10<spanclass=latexbold>(B)</span> 212<spanclass=latexbold>(C)</span> 12<spanclass=latexbold>(D)</span> 252<spanclass=latexbold>(E)</span> 15 <span class='latex-bold'>(A)</span>\ 10 \qquad <span class='latex-bold'>(B)</span>\ \frac{21}{2} \qquad <span class='latex-bold'>(C)</span>\ 12 \qquad <span class='latex-bold'>(D)</span>\ \frac{25}{2} \qquad <span class='latex-bold'>(E)</span>\ 15