MathDB
Triangular tangents

Source: 2017 AMC10 #22

February 8, 2017
AMCAMC 10geometry2017 AMC 10A

Problem Statement

Sides AB\overline{AB} and AC\overline{AC} of equilateral triangle ABCABC are tangent to a circle at points BB and CC respectively. What fraction of the area of ABC\triangle ABC lies outside the circle?
<spanclass=latexbold>(A)</span>43π2713<spanclass=latexbold>(B)</span>32π8<spanclass=latexbold>(C)</span>12<spanclass=latexbold>(D)</span>323π9<spanclass=latexbold>(E)</span>4343π27 <span class='latex-bold'>(A) </span>\dfrac{4\sqrt{3}\pi}{27}-\frac{1}{3}\qquad <span class='latex-bold'>(B) </span> \frac{\sqrt{3}}{2}-\frac{\pi}{8}\qquad <span class='latex-bold'>(C) </span> \frac{1}{2} \qquad <span class='latex-bold'>(D) </span>\sqrt{3}-\frac{2\sqrt{3}\pi}{9}\qquad <span class='latex-bold'>(E) </span> \frac{4}{3}-\dfrac{4\sqrt{3}\pi}{27}