document.write( "Question 253199: How do you find the area of a triangle if two sides are 4 inches and 5 inches and the included angle is 120 degrees? \n" ); document.write( "

Algebra.Com's Answer #185461 by drk(1908) $\"\"$ $\"About$

You can put this solution on YOUR website!
The formula you need here is
\n" ); document.write( "(i) $\"A+=+%281%2F2%29%2Aab%2Asin%28C%29\"$
\n" ); document.write( "where a and b are the sides and C is the \"included\" angle.
\n" ); document.write( "From (i) we have
\n" ); document.write( " $\"A+=+%281%2F2%29%2A%284%29%2A%285%29%2Asin%28120%29\"$
\n" ); document.write( "sin(120) = sqrt(3) / 2
\n" ); document.write( " $\"A+=+%281%2F2%29%2A20%2Asqrt%283%29%2F2\"$
\n" ); document.write( " $\"A+=+5%2Asqrt%283%29\"$
\n" ); document.write( " \n" ); document.write( "

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