Determine the value of x in this polygon.

Answer:
Step-by-step explanation:
It's the trapezoid.
We know: the sum of the angle measures at one leg of a trapezoid is 180°.
Therefore we have the equation:
[tex](x+12.5)+(6x+3)=180[/tex] combine like terms
[tex](x+6x)+(12.5+3)=180[/tex]
[tex]7x+15.5=180[/tex] subtract 15.5 from both sides
[tex]7x=164.5[/tex] divide both sides by 7
[tex]x=23.5[/tex]