Answer:
<em>Answer</em><em> </em><em>is</em><em> </em><em>-6</em>
Step-by-step explanation:

<em>HAVE A NICE DAY</em><em>!</em>
<em>THANKS FOR GIVING ME THE OPPORTUNITY</em><em> </em><em>TO ANSWER YOUR QUESTION</em><em>. </em>
Answer: Hope this helps :)

<h2><u><em>
Mark me as Brainliest please</em></u></h2>
Answer:
Step-by-step explanation:
1. 30
2. 23
3. 8
4.52
5.144
6.40
7. 210
8. 144
9. 135
10. 105
11. 2(207)
The formula for working out the total interior is:
180(n-2) = 1260
So let’s rearrange by dividing both sides by 180 and find what n is:
n-2 = 7
Then let’s add 2 to both sides to find what n is:
n=9
Each interior angle is 1260/9 = 140°.
The sum of the interior angle and its corresponding exterior angle is 180°.
Therefore, the polygon has 9 sides. :)