Beth simplified the expression 8 + 10 + 8 + 2 minus (4 times 1.4) minus (4 times 1.4) to find the perimeter of the figure on the grid. On a coordinate plane, a figure has side lengths of 8, 10, 8, 2, (4 times 1.4), (4 times 1.4).

What error did Beth make?
She found the area of the figure instead of the perimeter.
She subtracted the lengths of the diagonal lines instead of adding them.
She used 4 times 1.4 to represent the length of each diagonal line instead of 4.
She added the horizontal and vertical lengths instead of multiplying them.