Here you go :) I sent the work in the picture below
Answer:
Length is 90yards and width is 60yards
Step-by-step explanation:
Perimeter= 2( length+width)
let the width be x
then the length will be 30 + x
300 = 2(30+x+x)
150 = 30 + 2x
120= 2x
x = 120/2
x = 60 yards
length= 30+x
= 30 + 60
= 90yards
We can figure this out using the explicit formula.

n represents the term we are looking for.
f(1) represents the first term in the sequence, which in this case, is 7.
d represents the common difference, which in this case, is +3.
f(n) = 7 + 3(n - 1)
f(n) = 7 + 3n - 3
f(n) = 4 + 3n
Now, we can input 214 for n and solve.
f(214) = 4 + 3(214)
f(214) = 4 + 642
f(214) = 646
The 214th term in this sequence is 646.