Let the smaller polygon have side lengths a and the larger polygon have side lengths b. Since the polygons are similar, the ratio of corresponding side lengths is the same as the ratio of their areas. That is:
b^2 / a^2 = 128 / 98
Simplifying this expression, we get:
b / a = √(128 / 98) = √(64 / 49) = (8 / 7)
Now we can use the fact that the perimeter of the smaller polygon is 42 inches:
4a = 42
a = 10.5
Substituting this into the ratio we found above, we get:
b = (8 / 7) * a = (8 / 7) * 10.5 = 12
Therefore, the larger polygon has a perimeter of:
4b = 4 * 12 = 48 inches.