I estimated to 45 then divided 21 and got about 2.1
Answer:
4√7
Step-by-step explanation:
it's correct I m pretty sure but dat
Let the side length of the square be x, then A = x^2
but diagonal (z) = sqrt(2x^2)
z^2 = 2x^2
x^2 = 1/2 z^2
Thus, A = 1/2 z^2
dA/dz = 1/2 (2z) = z
The rate of change is z.
When z = 4, the rate is 4.
This will leave you with
140 = 2(40) + 2x
60 = 2x
30= x
So the length is 30.
