document.write( "Question 82091: Ina right triangle, sinB = 2/3, find the cosB \n" ); document.write( "

Algebra.Com's Answer #58815 by funmath(2933) $\"\"$ $\"About$

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In a right triangle, sinB = 2/3, find the cosB
\n" ); document.write( "In right triangle trigonometry:
\n" ); document.write( "If we call the hypotenuse (the longest side of a right triangle): c
\n" ); document.write( "The side opposite of an angle: b
\n" ); document.write( "The side adjacent to the angle: a
\n" ); document.write( "Then sine=b/c
\n" ); document.write( "and cosine=a/c
\n" ); document.write( "AND
\n" ); document.write( "according to the pythagorean theorem: $\"c%5E2=a%5E2%2Bb%5E2\"$
\n" ); document.write( "Our b=2 and c=3, using the pythagorean theorem, we can find a:
\n" ); document.write( " $\"%283%29%5E2=a%5E2%2B%282%29%5E2\"$
\n" ); document.write( " $\"9=a%5E2%2B4\"$
\n" ); document.write( " $\"9-4=a%5E2\"$
\n" ); document.write( " $\"5=a%5E2\"$
\n" ); document.write( " $\"sqrt%285%29=sqrt%28a%5E2%29\"$
\n" ); document.write( " $\"a=sqrt%285%29\"$
\n" ); document.write( "Therefore: $\"highlight%28cosB=sqrt%285%29%2F3%29\"$
\n" ); document.write( "Happy Calculating!!!!
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