![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
From the diagram adjacent side 3 the missing legth is adjecent to the angle measuring ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b546484d3b84467e9c8b11dd92931f36.png\")
and hypotenuse is x.
The trigonometric function relating adjacent side of a triangle and then adjacent is cosine function.
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=82e9731a20cae80856415f411dedc98e.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d0fad1566a058b4cbdc55d136dadccdc.png\")
(Substitute ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=01f8f99404a948277b8c64de930ac4ea.png\")
)
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4046e3ee6153b6c0c2595767600325a9.png\")
Apply cross product property ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4a768eb71c3beb8a2b4c32e7be25eb53.png\")
then ad = bc.
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4d827e4428c780d1507de04b7bf1f584.png\")
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The value of x is 6.