Answer:
1) 30
All of the exterior angles add to 360. There are 12 values of X there. 360 ÷ 12=30
2) 51.4286
360 ÷ 7 (7 exterior angles) = 51.42...
3) 16.
All of the angles given equal 247 take this from 360 = 113. We need to add twelve 125 and subtract 13 = 112 divide this by 7 (there are seven values of X there) = 16
4) 30 sides
360 ÷ 12 = 30
5) 360 is not divisible by 12.5 so there can't be a whole number of sides.
Hope this helps :)
