Answer:
1. x=158
2. x=58
3. x=68
4. the shape is a 20-gon
6. the shape has 52 sides
Explanation:
1. the sum of interior angles of a nonagon is 1260. You add all the numbers that are shown. that comes out to 1102. 1260-1102 is 158.
2. the sum of interior angles of a 4 sided shape is 360. you add 2x+5+2x+7+x+x and you get 6x+12. then you make an equation, 6x+12=360. subtract 12 from both sides and you get 6x=348. Divide by 6 on both sides and you get x=58
3. the sum of interior angles of a pentagon is 540. you add x-8+3x-11+x+8+2x+7+x and you get 8x-4. then you make an equation, 8x-4=540. you add 4 to both sides and you get 8x=544. Divide by 8 on both sides and you get x=68
4. I don't know how to find it, but I know that a 20-gon has the sum of interior angles that equals up to 3240. sorry
5. I am sorry, i don't know how to do that
6. use (n-2)180. n is the number of sides. replace n with 52. (52-2)180. (50)180 = 9000