MathDB
Circle in Circular Arcs

Source:

March 23, 2008
ratioanalytic geometryrotationgeometrypower of a pointPythagorean Theorem

Problem Statement

If circular arcs AC AC and BC BC have centers at B B and A A, respectively, then there exists a circle tangent to both AC \stackrel{\frown}{AC} and BC \stackrel{\frown}{BC}, and to AB \overline{AB}. If the length of BC \stackrel{\frown}{BC} is 12 12, then the circumference of the circle is [asy]unitsize(4cm); defaultpen(fontsize(8pt)+linewidth(.8pt)); dotfactor=3;
pair O=(0,.375); pair A=(-.5,0); pair B=(.5,0); pair C=shift(-.5,0)*dir(60); draw(Arc(A,1,0,60)); draw(Arc(B,1,120,180)); draw(A--B); draw(Circle(O,.375)); dot(A); dot(B); dot(C); label("AA",A,SW); label("BB",B,SE); label("CC",C,N);[/asy]<spanclass=latexbold>(A)</span> 24<spanclass=latexbold>(B)</span> 25<spanclass=latexbold>(C)</span> 26<spanclass=latexbold>(D)</span> 27<spanclass=latexbold>(E)</span> 28 <span class='latex-bold'>(A)</span>\ 24 \qquad <span class='latex-bold'>(B)</span>\ 25 \qquad <span class='latex-bold'>(C)</span>\ 26 \qquad <span class='latex-bold'>(D)</span>\ 27 \qquad <span class='latex-bold'>(E)</span>\ 28