step 1: Find the area of the triangle
The area of the triangle given is:
[tex]\begin{gathered} \text{Area = }\frac{1}{2}\times base\times height \\ =\frac{1}{2}\times4\times10 \\ =20ft^2 \end{gathered}[/tex]step 2: Find the dimension of rectangles that will give the same area as the triangle
The area of a rectangle is given by:
[tex]\text{Area}=\text{ length x width}[/tex][tex]\begin{gathered} \text{ option a: }1.6ftx25ft=40ft^2 \\ \text{option b: 5 ft x 16 ft =}80ft^2 \\ \text{option c: }3.5ftx4ft=14ft^2 \\ \text{option d: }0.4\text{ ft x 50 ft=}20ft^2 \end{gathered}[/tex]Therefore, the dimension of the rectangle with the same area as the triangle is
[tex]0.4\text{ ft}\times50\text{ ft}[/tex]OptionD is correct