Answer:
Step-by-step explanation:
The common difference, d, is 3, because the number of squares goes up by 3 each time.
d = 3
Number of squares in nth figure is:
a(n) = 4 + d(n - 1)
4 is the initial number of squares, d is how many it goes up each time, and we take n-1 because you need to account for the initial number of squares.
a(n) = 4 + d(n - 1)
For n = 200
a(n) = 4 + d(n - 1)
a(200) = 4 + 3(200-1)
a(200) = 4 + 3(199)
a(200) = 4 + 597
a(200) = 601
