Answer:
54 chickens
Step-by-step explanation:
This problem requires you find the area of Thomas's field, then use that area to find the number of chickens he can keep. The irregularly-shaped field can be considered as composed of shapes that you know how to find the area of.
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There are many ways the area can be divided. One of them is shown in the attachment. That shows the area to be the sum of the areas of a triangle and a trapezoid.
The triangle has a base of 20 m and a height of 7 m, so an area of ...
A = 1/2bh
A = 1/2(20 m)(7 m) = 70 m²
The trapezoid has bases of 11 m and 18 m, and a height of 14 m. Its area is ...
A = 1/2(b1 +b2)h
A = 1/2(11 m +18 m)(14 m) = 1/2(29 m)(14 m) = 203 m²
The area of the field is the sum of these areas:
field area = triangle area + trapezoid area
field area = 70 m² +203 m² = 273 m²
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Each chicken requires an area of 5 m², so the total area for n chickens is ...
area for n chickens = 5n . . . . square meters
This area cannot exceed the area of the field, so an inequality can be written:
area for n chickens ≤ field area
5n ≤ 273
n ≤ 54.6 . . . . . . divide by 5
Thomas can keep a maximum of 54 chickens in the field.