MathDB
Area of Quadrilateral in Triangle

Source:

January 5, 2007
geometrytrigonometrytrapezoidAMCAIMEangle bisector

Problem Statement

In the diagram below, angle ABCABC is a right angle. Point DD is on BC\overline{BC}, and AD\overline{AD} bisects angle CABCAB. Points EE and FF are on AB\overline{AB} and AC\overline{AC}, respectively, so that AE=3AE=3 and AF=10.AF=10. Given that EB=9EB=9 and FC=27FC=27, find the integer closest to the area of quadrilateral DCFG.DCFG.
[asy] size(250); pair A=(0,12), E=(0,8), B=origin, C=(24*sqrt(2),0), D=(6*sqrt(2),0), F=A+10*dir(A--C), G=intersectionpoint(E--F, A--D); draw(A--B--C--A--D^^E--F); pair point=G+1*dir(250); label("AA", A, dir(point--A)); label("BB", B, dir(point--B)); label("CC", C, dir(point--C)); label("DD", D, dir(point--D)); label("EE", E, dir(point--E)); label("FF", F, dir(point--F)); label("GG", G, dir(point--G)); markscalefactor=0.1; draw(rightanglemark(A,B,C)); label("10", A--F, dir(90)*dir(A--F)); label("27", F--C, dir(90)*dir(F--C)); label("3", (0,10), W); label("9", (0,4), W);[/asy]