document.write( "Question 433239: Hi, I need help with this problem, mainly just how to come up with an equation to use in the Quadratic Formula. Thanks!\r
\n" ); document.write( "\n" ); document.write( "The Garys have a triangular pennant of area 420 in^2 flying from the flagpole in their yard. the height of the triangle is 10in less than 5 times the base of the triangle. What are the dimensions of the pennant? \n" ); document.write( "
Algebra.Com's Answer #300353 by nerdybill(7384)\"\" \"About 
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The Garys have a triangular pennant of area 420 in^2 flying from the flagpole in their yard. the height of the triangle is 10in less than 5 times the base of the triangle. What are the dimensions of the pennant?
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\n" ); document.write( "We know that for ANY triangle:
\n" ); document.write( "area = (1/2)bh
\n" ); document.write( "where
\n" ); document.write( "b is length of the base
\n" ); document.write( "h is length of the height
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\n" ); document.write( "Let b = base of triangle
\n" ); document.write( "then from \"the height of the triangle is 10in less than 5 times the base\" we get
\n" ); document.write( "5b-10 = height
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\n" ); document.write( "our equation:
\n" ); document.write( "420 = (1/2)b(5b-10)
\n" ); document.write( "840 = b(5b-10)
\n" ); document.write( "840 = 5b^2 - 10b
\n" ); document.write( "0 = 5b^2 - 10b - 840
\n" ); document.write( "0 = b^2 - 2b - 168
\n" ); document.write( "0 = (b+12)(b-14)
\n" ); document.write( "b = {-12, 14}
\n" ); document.write( "We can throw out the negative solution leaving:
\n" ); document.write( "b = 14 inches (base)
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\n" ); document.write( "height then:
\n" ); document.write( "5b-10 = 5(14)-10 = 70-10 = 60 inches\r
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