document.write( "Question 1062658: A right triangle is formed with vertices at the points (7,-2), (19,7), and (-5,14). What percent of the triangle's area lies in the fourth quadrant? \n" ); document.write( "

Algebra.Com's Answer #677619 by Edwin McCravy(20055) $\"\"$ $\"About$

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document.write( "The part of triangle ABC that lies in the fourth quadrant\r\n" );
document.write( "is the triangle DAE.\r\n" );
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document.write( "You find the area of triangle ABC by the determinant:\r\n" );
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document.write( "The area of triangle ABC is 300.\r\n" );
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document.write( "You must now find the area of triangle DAE\r\n" );
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document.write( "But to do that you must find the coordinates of D and E:\r\n" );
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document.write( "You find the equation of line CA by using the slope formula: \r\n" );
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document.write( "and the point-slope formula \r\n" );
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document.write( "and after doing that and simplifying, you get the equation \r\n" );
document.write( "of line CA, which is,\r\n" );
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document.write( "4x + 3y = 22 \r\n" );
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document.write( "Then point D is the x-intercept of line CA, so substitute 0 for y\r\n" );
document.write( "and solve for x and get the coordinates of D as\r\n" );
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document.write( "Now exactly the same way, you'll find the equation of the line BE\r\n" );
document.write( "as \r\n" );
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document.write( "3x - 4y = 29\r\n" );
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document.write( "Then point E is the x-intercept of line BA, so substitute 0 for y\r\n" );
document.write( "and solve for x and get the coordinates of E as\r\n" );
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document.write( "Then use the matrix method again to find the area of triangle DAE:\r\n" );
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document.write( "Finally you need to find what percent 25/3 is of 300.\r\n" );
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document.write( "So you divide \r\n" );
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document.write( "So the area of triangle DAE is 1/36th of the area of triangle ABC.\r\n" );
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document.write( "To find out what percent that is, we multiply by 100%\r\n" );
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document.write( "Edwin

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