document.write( "Question 431186: Let C be a circle with center O and radius r. Let P be a point such that OP = d > r. Find the length of the tangent line from P to C? HELP! \n" ); document.write( "

Algebra.Com's Answer #299347 by Edwin McCravy(20056) $\"\"$ $\"About$

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document.write( "A tangent to a circle makes a right angle with the\r\n" );
document.write( "radius drawn to the point of tangency. So the triangle\r\n" );
document.write( "drawn is a right triangle and the hypotenuse is d.\r\n" );
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document.write( "We want to find x.\r\n" );
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document.write( "Use the Pythagorean theorem:\r\n" );
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document.write( "r² + x² = d²\r\n" );
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document.write( "     x² = d² - r²\r\n" );
document.write( "           _______ \r\n" );
document.write( "      x = √d² - r²  \r\n" );
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document.write( "Edwin

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