Question 1099868
{{{ sin( theta ) = 4/7 }}}
{{{ 4 }}} = side opposite {{{ theta }}}
{{{ b }}} = side adjacent to {{{ theta }}}
{{{ 7 }}} = hypotenuse 
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{{{ cos( theta ) = b/7 }}}
{{{ b^2 = 7^2 - 4^2 }}}
{{{ b^2 = 49 - 16 }}}
{{{ b^2 = 33 }}}
{{{ b = sqrt( 33 ) }}}
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{{{ cos( theta ) = sqrt( 33 ) / 7 }}}