Answer:i think its the second choice sorry if im wrong
Step-by-step explanation:
The area would be 144cm^2.
In order to find the area, we need to know the length of the rectangle. We can find that using the perimeter formula.
2l + 2w = P
2l + 2(36) = 80
2l + 72 = 80
2l = 8
l = 4
So now that we know the length is 4, we can find the area using that formula.
A = lw
A = (4)(36)
A = 144
Answer:



Step-by-step explanation:
Let
x----> the length of the rectangular garden
y---> the width of the rectangular garden
we know that
The perimeter of the rectangle is equal to

we have

so

simplify

------> equation A
Remember that the area of rectangle is equal to
----> equation B
substitute equation A in equation B
----> this is a vertical parabola open downward
The vertex is a maximum
The y-coordinate of the vertex is the maximum area
The x-coordinate of the vertex is the length side of the rectangle that maximize the area
using a graphing tool
The vertex is the point 
see the attached figure
so

Find the value of y

The garden is a square
the area is equal to
----> is equal to the y-coordinate of the vertex is correct
Answer:
The width of the window should be
and the height of the window should be 
Step-by-step explanation:
we know that
The circumference of a semicircle (window) is equal to

we have that


substitute and solve for r


so
the width of the window is equal to the diameter of the semicircle
so
The width of the window should be
and the height of the window should be 