The sum of the interior angles of a heptagon 900º, if you know 6 of the 7 interior angles of the heptagon, you can determine the measure of the seventh angle as follows:
[tex]\begin{gathered} 900=111+110+121+135+139+92+x \\ 900=708+x \end{gathered}[/tex]Subtract 708 from both sides of the equal sign to reach the measure of the seventh angle:
[tex]\begin{gathered} 900-708=708-708+x \\ 192=x \end{gathered}[/tex]The seventh interior angle has a measure of 192º
