Question 831482
The measures of the interior angles of any polygon with {{{n}}} sides add up to
{{{(n-2)*180^o}}} .
An octagon has {{{8}}} sides.
The measures of the interior angles of any octagon add up to
{{{(8-2)*180^o=6*180^o=1080^o}}}
So,
{{{140^o+1400^o+1300^o+1300^o+1500^o+1450^o+1150^o+d=1080^o}}}
{{{950^o+d=1080^o}}}
{{{d=1080^o-950^o}}}
{{{highlight(d=130^o)}}}