To find the sum of interior angles of this polygon you have to use the equation
S=180(n-2)
where n is the number of sides
S=180(6-2)
S=180(4)
S=720 degrees
The sum of all angles is 720 degrees
[tex]110 + x + 25 + x - 30 + x + x + 115 = 720[/tex]
[tex]4x = 720 - 110 - 25 - 115 + 30[/tex]
[tex]4x = 720 - 220[/tex]
[tex]4x = 500[/tex]
[tex]x = \frac{500}{4} = 125[/tex]
