How many rectangles are in the array below?

[asy]
for(int i = 0; i<3; ++i)
{

for(int j = 0; j<3; ++j)

{

draw((3i,j)--(3i+3,j)--(3i+3,j+1)--(3i,j+1)--(3i,j)--cycle,linewidth(2));

}
}
[/asy]
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
How many rectangles are in the array below?

[asy]
for(int i = 0; i<3; ++i)
{

for(int j = 0; j<3; ++j)

{

draw((3i,j)--(3i+3,j)--(3i+3,j+1)--(3i,j+1)--(3i,j)--cycle,linewidth(2));

}
}
[/asy]
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
36
How many rectangles are in the array below?

[asy]
for(int i = 0; i<3; ++i)
{

for(int j = 0; j<3; ++j)

{

draw((3i,j)--(3i+3,j)--(3i+3,j+1)--(3i,j+1)--(3i,j)--cycle,linewidth(2));

}
}
[/asy]
train