Answer: 3 feet by 10 feet rectangle
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Step-by-step explanation:
Assuming this garden is a rectangle, it has dimensions L and W which are the length and width respectively.
perimeter of rectangle = 2*(length+width)
P = 2*(L+W)
26 = 2(L+W) ... plug in given perimeter
26/2 = L+W .... divide both sides by 2
13 = L+W
13-W = L .... isolate L by subtracting W from both sides
L = 13-W
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Area of rectangle = Length*Width
A = L*W
A = (13-W)W .... replace L with 13-W
A = W(13-W)
A = 13W - W^2 ..... distribution
30 = 13W - W^2 .... plug in given area A = 30
W^2 - 13W + 30 = 0 ... get everything to one side
(W - 10)(W - 3) = 0 ...... factor
W-10 = 0 or W-3 = 0 ...... zero product property
W = 10 or W = 3
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If the width is W = 10, then
L = 13-W
L = 13-10
L = 3 is the length
Or if the width is W = 3, then
L = 13-W
L = 13-3
L = 10 is the length
Either way, this is a 3 ft by 10 ft rectangle
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Check:
Area = length*width = 10*3 = 30 square feet
perimeter = 2(length+width) = 2*(10+3) = 2*13 = 26 feet
or you could say
perimeter = L+W+L+W = 10+3+10+3 = 13+13 = 26 feet
we get the correct area and perimeter, so this confirms our answer.