The given angle is ;
From the diagram are vertical angles.
Since vertical angles have same measure, .
The angle .
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=92f53928c66088756f59706dd8e9f68d.png\")
; ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0a6b7681e5c30d091c23f21aa6be0091.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=314924a29e66420541e89399e3c87e46.png\")
are vertical angles.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=980a2f7fb5e41ea91be705ae11bb70a9.png\")
.![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
.