Answer:
8π in
64π mm²
Step-by-step explanation:
The circumference of a circle is equal to 2πr, where r is the radius.
2π(4) = 8π ≈ 25.132
The area of a circle is equal to πr²
π(8)² = 64π ≈ 201.062
We want to find the value that makes

To find it we must look at the standard normal table, using the complementary cumulative table we find that

Then, using the z-score we can find the minimum score needed, remember that

Where
σ = standard deviation
μ = mean
And in our example, x = minimum score needed, therefore

Rounding to the nearest integer the minimum score needed is 568, if you get 568 you are at the top 20.1%.
We know that
if two lines are perpendicular
then
the slopes
m1*m2=-1
step 1
find the slope AB
A (0,2)
B (-3,-3)
m=(y2-y1)/(x2-x1)-----> m=(-3-2)/(-3-0)-----> m=-5/-3----> m1=5/3
step 2
find the slope CD
C (-4,1)
D (0,-2)
m=(y2-y1)/(x2-x1)-----> m=(-2-1)/(0+4)-----> m=--3/4----> m2=-3/4
step 3
multiply mi*m2
(5/3)*(-3/4)-----> -15/12
so
15/12 is not -1
therefore
AB is not perpendicular to CD