Answer:
360 degrees
Explanation:
Well, we can go about this two ways
Let's just use the sum of a flat line in terms of degrees to find it
So the equation is:
(180-71)+(180-124)+(180-76)+(180-89)
Simplify that and you get 360
The other way you can do it is that 71+124+76+89=360. Since this is a polygon, that means the sum of all its interior angles will be 360 and that means that all of the exterior angles, since their all practically just opposites of the interior angles, also add up to 360.
Tell me if you have any questions.