Use the following polygon to find "x":
|(2x + 20) (3x – 10)
(2x)
(2x - 10)

Answer:
[tex]2x + 20 + 2x + 3x - 10 + 2x - 10 = 360[/tex]
[tex]9x = 360[/tex]
[tex]x = 40[/tex]