document.write( "Question 58585: 146. Height of a post. Betty observed that the lamppost in the front of her house cases a show of length 8 feet when the angle of inclination of the sun is 60 degrees. How tall is the lamppost? (In a 30-60-90 right triangle, the side opposite 30 is one-half the length of the hypotenuse)\r
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Algebra.Com's Answer #40140 by Edwin McCravy(20059)\"\" \"About 
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Height of a post. Betty observed that the lamppost in the front of her house\r\n" );
document.write( "cases a show of length 8 feet when the angle of inclination of the sun is 60\r\n" );
document.write( "degrees. How tall is the lamppost? (In a 30-60-90 right triangle, the side\r\n" );
document.write( "opposite 30 is one-half the length of the hypotenuse) \r\n" );
document.write( "not sure how to solve \r\n" );
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document.write( "                |\r\n" );
document.write( "              - O -\r\n" );
document.write( "                |\r\n" );
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document.write( "                       \r\n" );
document.write( "          |\r\n" );
document.write( "        --o--\r\n" );
document.write( "         /|\r\n" );
document.write( "        / | \r\n" );
document.write( "     h /  | \r\n" );
document.write( "      /30°|x\r\n" );
document.write( "     /    | \r\n" );
document.write( "    /     | \r\n" );
document.write( "   /60°   |\r\n" );
document.write( "   ¯¯¯¯¯¯¯\r\n" );
document.write( "     8 ft\r\n" );
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document.write( "Let x be the height of the lamp post. I have marked\r\n" );
document.write( "the hypotenuse h. The shadow is the line marked 8 ft. \r\n" );
document.write( "It is the side opposite the 30° angle. Therefore \r\n" );
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document.write( "h = 2 × 8 ft or 16 ft. \r\n" );
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document.write( "I will now re-draw the picture putting\r\n" );
document.write( "16 ft. where the h is:\r\n" );
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document.write( "                |\r\n" );
document.write( "              - O -\r\n" );
document.write( "                |\r\n" );
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document.write( "\r\n" );
document.write( "                       \r\n" );
document.write( "          |\r\n" );
document.write( "        --o--\r\n" );
document.write( "         /|\r\n" );
document.write( "        / | \r\n" );
document.write( "    16 /  | \r\n" );
document.write( "      /30°|x\r\n" );
document.write( "     /    | \r\n" );
document.write( "    /     | \r\n" );
document.write( "   /60°   |\r\n" );
document.write( "   ¯¯¯¯¯¯¯\r\n" );
document.write( "     8 ft\r\n" );
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document.write( "Now we can use the Pythagorean theorem\r\n" );
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document.write( "       c² = a² + b²\r\n" );
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document.write( "where c = 16, a = 8, and b = x. Substitute these\r\n" );
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document.write( "       c² = a² + b²\r\n" );
document.write( "    (16)² = (8)² + x²\r\n" );
document.write( "      256 = 64 + x²\r\n" );
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document.write( "Subtract 64 from both sides\r\n" );
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document.write( "      192 = x²\r\n" );
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document.write( "Take square root of both sides:\r\n" );
document.write( "      ___\r\n" );
document.write( "     Ö192 = x\r\n" );
document.write( "     13.9 = x\r\n" );
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document.write( "The lampost is approximately 13.9 ft tall.\r\n" );
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document.write( "Edwin
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