A teacher has 36 students who were randomly assigned to 6 rows of 6 desks. She wants to survey the students about the homework policy. Which of the following uses cluster sampling?
Roll a fair number cube. Use the number rolled to pick a row of students. Survey every student in that row.
List the students according to their grade in the class. Survey one A student, one B student, etc.
For each row, flip a coin. If it is heads, survey all the boys in that row. If it is tails, survey all the girls in that row.
Select a student by rolling a fair number cube twice. The first roll gives the row number, and the second roll gives
the seat number. Then repeat.

i think the answer is fried chicken ; >

step-by-step explanation:

i need a picture

step-by-step explanation:

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240