Answer:
[tex]x=144[/tex]
Step-by-step explanation:
[tex]We\ can\ observe\ that:\\The\ polygon\ is\ an\ octagon\ as\ it\ is\ bounded\ by\ 8\ linear\ sides.\\Hence,\\We\ know\ that,\\The\ Interior\ Angle\ Sum\ of\ a\ polygon\ with\ n\ is\ given\ by\ the\ formula:\\Interior\ Angle\ Sum=180(n-2)\\Hence,\\As\ we\ already\ know\ that,\\The\ number\ of\ sides\ in\ this\ polygon=n=8\\Hence,\\The\ Interior\ Angle\ Sum\ Of\ An\ Octagon=180(8-2)=180*6=1080\\[/tex]
[tex]Hence,\\\angle 1+ \angle 2+\angle 3+\angle 4+\angle 5+\angle 6+\angle 7+\angle 8=1080\\Hence,\\129+132+136+124+141+158+116+x=1080\\Hence,\\936+ \angle x=1080\\\angle x=1080-936=144[/tex]
