The area of the trapezoid with the given bases and height is 30ft².
The area of a trapezoid is expressed mathematically as;
A = ( b₁+b₂ )/2 × h
Where b₁ is length of base b₁, b₂ is length of base b₂ and h is height.
Given the data in the question;
Plug the given values into the equation above.
A = ( b₁+b₂ )/2 × h
A = ( 4ft + 8ft )/2 × 5ft
A = ( 12ft )/2 × 5ft
A = 6ft × 5ft
A = 30ft²
Therefore, the area of the trapezoid with the given bases and height is 30ft².
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