MathDB
Lines and Circles

Source:

February 7, 2009
geometrysimilar triangles

Problem Statement

The straight line AB \overline{AB} is divided at C C so that AC\equal{}3CB. Circles are described on AC \overline{AC} and CB \overline{CB} as diameters and a common tangent meets AB AB produced at D D. Then BD BD equals: <spanclass=latexbold>(A)</span> diameter of the smaller circle<spanclass=latexbold>(B)</span> radius of the smaller circle<spanclass=latexbold>(C)</span> radius of the larger circle<spanclass=latexbold>(D)</span> CB3<spanclass=latexbold>(E)</span> the difference of the two radii <span class='latex-bold'>(A)</span>\ \text{diameter of the smaller circle} \\ <span class='latex-bold'>(B)</span>\ \text{radius of the smaller circle} \\ <span class='latex-bold'>(C)</span>\ \text{radius of the larger circle} \\ <span class='latex-bold'>(D)</span>\ CB\sqrt{3}\\ <span class='latex-bold'>(E)</span>\ \text{the difference of the two radii}