The proportion is .
Apply cross product property: If , then .
(Cross products)
(Multiply: )
The value of .
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=73e640832f94089e7ccd9f3c6a94d363.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4a768eb71c3beb8a2b4c32e7be25eb53.png\")
, then ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cbc831e12eb457a0405bb3a07af0ec3c.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8b45a7846c04f3f4320789b57283be5a.png\")
(Cross products)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b987e62c7e279160697698c64e0e3824.png\")
(Multiply: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c3a7120d18aa1a7126758b412ceff762.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
.