MathDB
Basic Perimeter

Source:

March 27, 2006
geometryperimeter

Problem Statement

A triangular corner with side lengths DB=EB=1DB=EB=1 is cut from equilateral triangle ABCABC of side length 33. The perimeter of the remaining quadrilateral is
[asy] draw((0,0)--(2,0)--(2.5,.87)--(1.5,2.6)--cycle, linewidth(1)); draw((2,0)--(3,0)--(2.5,.87)); label("3", (0.75,1.3), NW); label("1", (2.5, 0), S); label("1", (2.75,.44), NE); label("A", (1.5,2.6), N); label("B", (3,0), S); label("C", (0,0), W); label("D", (2.5,.87), NE); label("E", (2,0), S);[/asy]
(A) 6(B) 612(C) 7(D) 712(E) 8\text{(A)} \ 6 \qquad \text{(B)} \ 6\frac12 \qquad \text{(C)} \ 7 \qquad \text{(D)} \ 7\frac12 \qquad \text{(E)} \ 8