If the area of the parallelogram ABCD is 4 square feet and OP"=5OP, what is the area of the parallelogram A"B"C"D"?

To find the area of the parallelogram A"B"C"D", we need more information about the relationship between the two parallelograms. Specifically, we need to know the corresponding side lengths or angles between the two parallelograms.

However, let's assume that the two parallelograms A"B"C"D" and ABCD are similar. This means that the corresponding angles between the two parallelograms are equal, and the corresponding side lengths are in proportion.

Since the area of the parallelogram ABCD is given as 4 square feet, we can denote its base as b and its height as h. The formula for the area of a parallelogram is A = base × height, so we have A = b × h = 4.

Now, the ratio between the bases of the two parallelograms is given as OP" = 5 OP. Let's denote OP as x. So, OP" = 5x.

If the height of ABCD is h, we assume that the height of A"B"C"D" is also h' (proportional to the height of ABCD). Since the ratios of the corresponding sides are equal, we have:

h'/h = OP"/OP

Substituting the given values, we get:

h' / h = (5x) / x
h' / h = 5

This means the height of A"B"C"D" is five times the height of ABCD.

Since the areas of similar shapes are proportional to the square of the ratio of their corresponding side lengths, we can conclude that the area of A"B"C"D" is equal to the area of ABCD multiplied by the square of the ratio of their corresponding side lengths:

Area of A"B"C"D" = 4 × (5^2) = 4 × 25 = 100 square feet.

Therefore, assuming the two parallelograms are similar, the area of A"B"C"D" would be 100 square feet.