Answer:
The formula to get the circumference of a circle is
but in this case we see that a diameter is being used therefore we can get rid of the 2 and the r because that is what the diameter and just replace d into there like this
.
We can then input the value and we get that
which then just narrows down to
.
<u><em>Hope this helps! Let me know if you have any questions</em></u>
So firstly, we have to find the LCD, or lowest common denominator, of 9 and 7. To do this, list the multiples of 9 and 7 and the lowest multiple they share is going to be your LCD. In this case, the LCD of 9 and 7 is 63. Multiply x^2/9 by 7/7 and 2y/7 by 9/9:

Next, add the numerators together, and your answer will be: 
Answer:
6 mm and 9 mm are the dimensions of the piece of plastic.
Step-by-step explanation:
Keep in mind the formulas for the area and perimeter of a rectangle:
A = lw
P = 2 (l + w)
List the factors of 54:
1, 2, 3, 6, 9, 18, 27, 54
POSSIBLE DIMENSIONS of the piece of plastic:
1 mm and 54 mm:
Area - 54 mm^2
Perimeter - 110 mm
2 mm and 27 mm
Area - 54 mm^2
Perimeter - 58 mm
3 mm and 18 mm
Area - 54 mm^2
Perimeter - 42 mm
6 mm and 9 mm
Area - 54 mm^2
Perimeter - 30 mm
The rectangular piece of plastic with the dimensions 6mm and 9 mm corresponds with the area and perimeter of the piece of plastic mentioned. So these are the correct dimensions.
Hope this helps!