Step-by-step explanation:
The 5 pieces that remained created an angle that measured 200 degree means that the 4 pieces made 360-200 degrees 160o.
If all four made 160 then each has to be 160/4 = 40o
200/5 also gives you 40 (the five remaining)
360/9 would also give you 40 9the 5 remaining and the 4 eaten)
I hope this helps
