document.write( "Question 1150432: Two circles are tangent to each other at A and the centre of the larger circle is at C. The lines AB and FC are perpendicular diameters of the larger circle. If BD = 9 cm and FE = 5 cm, then what is the radius of the smaller circle, in centimeters?
\n" ); document.write( "https://imgur.com/JdxYhZW
\n" ); document.write( "

Algebra.Com's Answer #771831 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "The statement of the problem is faulty; but the intent is clear. FC is a radius, not a diameter; let G be the point on the large circle that makes FG a diameter.

\n" ); document.write( "Let H be the other point of intersection of the small circle with diameter FG.

\n" ); document.write( "Let x be the length of segment CD.

\n" ); document.write( "Since BD = 9, the radius of the large circle is x+9. In particular, AC = 9

\n" ); document.write( "Since EF = 5, CE = CH = x+4..

\n" ); document.write( "AD and EH are chords of the small circle, intersecting at C. From the theorem about the lengths of the pieces of two intersecting chords in a circle,

\n" ); document.write( "\"x%28x%2B9%29+=+%28x%2B4%29%28x%2B4%29\"
\n" ); document.write( "\"x%5E2%2B9x+=+x%5E2%2B8x%2B16\"
\n" ); document.write( "\"x+=+16\"

\n" ); document.write( "The diameter of the small circle is x + (x+9) = 2x+9 = 41.

\n" ); document.write( "So the radius of the small circle is 20.5.
\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );