Question

HELP PLEASE!!!!!!!!!!!

The sum of all but one interior angle of an octagon is 776°. The measure of the final interior angle is ___ degrees.

Answer 1

the sum of all interior angles in a polygon, regular or not is

180( n - 2), n = number of sides

now, this is an octagon, with 8 sides, so it has a total of interior angles of 180( 8 - 2) or 180(6) = 1080.

we know the sum of all BUT one is 776°, so the last one must be 1080° - 776° = 304°.