Answer:
[tex]PQ = x + 13[/tex]
The dimension of the garden is 52.5ft by 43.5ft
Step-by-step explanation:
Given
The shape above
Required
Determine PQ
Determine dimension of the garden
Calculating Length PQ
Represent the length of the inner rectangle as L
Represent the width of the inner rectangle as W
[tex]W = x[/tex]
[tex]L = x + 9[/tex]
The distance between the inner rectangle and the outer triangle is 4ft
This implies that;
[tex]PQ = L + 4[/tex]
Substitute [tex]x + 9[/tex] for [tex]L[/tex]
[tex]PQ = x + 9 + 4[/tex]
[tex]PQ = x + 13[/tex]
Also;
[tex]QR = W + 4[/tex]
Substitute [tex]x[/tex] for [tex]W[/tex]
[tex]QR = x + 4[/tex]
Calculating The Dimension of The Garden
First, we need to determine the Area of the inner rectangle
[tex]Area_1 = L * W[/tex]
Recall that [tex]W = x[/tex] and [tex]L = x + 9[/tex]
So;
[tex]Area_1 = x * (x + 9)[/tex]
For the bigger rectangle
[tex]Area_2 = PQ * QR[/tex]
Recall that [tex]PQ = x + 13[/tex] and [tex]QR = x + 4[/tex]
So;
[tex]Area_2 = (x + 13)(x + 4)[/tex]
Given that the Area of the walkway is [tex]400ft^2[/tex]
This implies that
[tex]Area_2 = Area_1 + 400[/tex]
Substitute [tex]Area_1 = x * (x + 9)[/tex] and [tex]Area_2 = (x + 13)(x + 4)[/tex]
[tex](x + 13)(x + 4) = x * (x + 9) + 400[/tex]
Open All Brackets
[tex]x^2 + 13x + 4x + 52 = x^2 + 9x + 400[/tex]
[tex]x^2 + 17x + 52 = x^2 + 9x + 400[/tex]
Collect Like Terms
[tex]x^2 - x^2 + 17x - 9x = 400- 52[/tex]
[tex]8x = 348[/tex]
Divide both sides by 8
[tex]\frac{8x}{8} = \frac{348}{8}[/tex]
[tex]x = \frac{348}{8}[/tex]
[tex]x =43.5[/tex]
Since the dimensions of the garden is [tex]W = x[/tex] and [tex]L = x + 9[/tex]
Substitute 43.5 for x in both cases
[tex]L = 43.5 + 9 = 52.5[/tex]
[tex]W = 43.5[/tex]
Hence, the dimension of the garden is 52.5ft by 43.5ft
