document.write( "Question 1081672: The points A and C lie on a circle with center O and radius 5 sq.root of 2. The point within the circle is such that ABC = 90 degrees. Following the data:
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Algebra.Com's Answer #695968 by ikleyn(52790)\"\" \"About 
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\n" ); document.write( "The points A and C lie on a circle with center O and radius 5 sq.root of 2. The point within the circle is such that ABC = 90 degrees.
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\n" ); document.write( "\n" ); document.write( "It seems this problem is slightly above the average school geometry level.
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document.write( "0.  Make a sketch to follow my arguments.\r\n" );
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document.write( "    You have the circle of the radius \"5%2Asqrt%282%29\" with the center at the point O.\r\n" );
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document.write( "    You have the right-angled triangle ABC leaning on the chord AC.\r\n" );
document.write( "    The legs AB and BC are of the lengths 6 and 2 units.\r\n" );
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document.write( "1.  Hence, the length of the chord AC (which is the hypotenuse) is\r\n" );
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document.write( "    |AC| = \"sqrt%286%5E2%2B2%5E2%29\" = \"sqrt%2840%29\".\r\n" );
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document.write( "2.  The distance from the center O to the chord AC is \"sqrt%28R%5E2+-+%28abs%28AC%29%2F2%29%5E2%29\" = \"sqrt%28%285%2Asqrt%282%29%29%5E2+-+%28sqrt%2840%29%2F2%29%5E2%29\" = \"sqrt%2850-10%29\" = \"sqrt%2840%29\".\r\n" );
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document.write( "    It is the length of the perpendicular OD drown from the center O to the mid-point D of the chord AC.\r\n" );
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document.write( "3.  Draw the altitude BE in the right angled triangle ABC from the right angle vertex to the hypotenuse AC.\r\n" );
document.write( "    (E is the base of this altitude).\r\n" );
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document.write( "    You can find the length of BE from the \"AREA\" equation of the triangle ABC:\r\n" );
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document.write( "    \"%281%2F2%29%2Aabs%28AC%29%2Aabs%28BE%29\" = \"%281%2F2%29%2A2%2A6\",   ====>  |BE| = \"12%2Fsqrt%2840%29\".\r\n" );
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document.write( "4.  Now you can calculate one component of the segment OB.\r\n" );
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document.write( "    (I call this component \"vertical\" component of the segment OB, since it is vertical component in my sketch . . . )\r\n" );
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document.write( "    This vertical component is  |OD| - |BE| = \"sqrt%2840%29+-+12%2Fsqrt%2840%29\".\r\n" );
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document.write( "5. Next step is to find the horizontal component of the segment OB.\r\n" );
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document.write( "   For it, you need to determine in which segments the altitude DE divide the hypotenuse AC.\r\n" );
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document.write( "    It is very standard task (sub-task), and every advanced student must be able to do it.\r\n" );
document.write( "        (Use similarity of right-angled triangles).\r\n" );
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document.write( "    When you complete this sub-task, you will get the horizontal component of the segment OB by subtracting half of the chord AC length.\r\n" );
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document.write( "6.  Having the horizontal and the vertical components of OB, you will be in position to find its length.\r\n" );
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