Answer: (b) 48 cm
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Explanation:
Divide the perimeter of the square over 4 to get the side length s.
s = P/4
s = 48/4
s = 12
The side length of the square is 12 cm. This leads to an area of...
A = s^2
A = 12^2
A = 144
The area of the square is 144 square cm.
The rectangle is 4 cm^2 less than the square's area, so we know the rectangle has area 144-4 = 140 cm^2.
If the length of the rectangle is 14 cm, then the width must be
W = A/L
W = 140/14
W = 10
This is a 14 cm by 10 cm rectangle (note how 14*10 = 140)
The last step is to compute the perimeter of the rectangle
P = 2(L+W)
P = 2(14+10)
P = 2*24
P = 48
You can use the formula P = 2L+2W, but it's effectively the same thing.
The perimeter of the rectangle is 48 cm.
