a rectangular garden 50m long and 34m wide is surrounded by a uniform dirt road. find the width of the road if the total area is 540m²
Answers
Step-by-step explanation:
l = 50 m
b = 34 m
Perimeter = 2(l+b)
=2(50m+34m)
=2*84m
=168m
Area is 34m*50m
=1700m²
Hope it helps you
The width of the dirt road is 16 m.
Given:
A rectangular garden 50m long and 34m wide is surrounded by a uniform dirt road.
To Find:
The width of the road if the total area is 5400m².
Solution:
Let us consider the case of the garden alone.
The length of the garden = 50m
The width of the garden = 34m.
Hence, the area of the garden (which is in the shape of a rectangle)
= length x width = 50 x 34 = 1700m².
Now, a uniform dirt road surrounds the rectangular garden, such that the area of the garden along with the dirt road = 5400m².
Since the dirt road is uniform, let us assume that its width = y m.
The dirt road has extensions on two sides of the length as well as the width of the garden.
Hence, the new dimensions of the entire area (garden + road) then turn out to be:
The new length, l' = (50+2y).
The new length, w' = (34+2y).
⇒ The new area = l' x w' = (50+2y) x (34+2y).
⇒ 5400 = (50+2y) x (34+2y).
⇒ y² + 42y - 925 = 0
Let us use completing the square method to find out the required factors. The coefficient of y = 42.
Taking half of it becomes 42/2 = 21. Squaring 21 and adding it to both sides we get,
y² +42y + 441 = 925 + 441
⇒ (y+21)² = 1366
⇒ (y+21) = √1366 ≈ 37
⇒ y = 16
Hence the width of the dirt road is 16 m.
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