MathDB
Region with Squares and Triangles

Source: AMC 12 2008B Problem 15

February 29, 2008
geometrytrapezoidtrigonometryAMC

Problem Statement

On each side of a unit square, an equilateral triangle of side length 1 is constructed. On each new side of each equilateral triangle, another equilateral triangle of side length 1 is constructed. The interiors of the square and the 12 triangles have no points in common. Let R R be the region formed by the union of the square and all the triangles, and S S be the smallest convex polygon that contains R R. What is the area of the region that is inside S S but outside R R? <spanclass=latexbold>(A)</span>  14<spanclass=latexbold>(B)</span>  24<spanclass=latexbold>(C)</span>  1<spanclass=latexbold>(D)</span>  3<spanclass=latexbold>(E)</span>  23 <span class='latex-bold'>(A)</span> \; \frac{1}{4} \qquad <span class='latex-bold'>(B)</span> \; \frac{\sqrt{2}}{4} \qquad <span class='latex-bold'>(C)</span> \; 1 \qquad <span class='latex-bold'>(D)</span> \; \sqrt{3} \qquad <span class='latex-bold'>(E)</span> \; 2 \sqrt{3}