Answer
$1080^o$
Work Step by Step
RECALL:
The total measurement of the angles of a polygon with $n$ sides is given by the formula:
$180^o(n-2)$
An octagon has 8 sides.
Thus, the sum of the angles inside an octagon is:
$=180^o(8-2)
\\=180^o(6)
\\=1080^o$
