On problems ii, and iii, you just count up the amount of sides on the polygon and add x behind it to create a type of an equation to find the perimeter of that shape that will work as longs as the sides are congruent to each other.
For problems a,b, and c, you just have to calculate what x is. On a, you find what the other side is if one side is 2 and the area is 24. On b you find what the other side could equal if one side is 4 and the area is 16. On c you know what the perimeter is (72) . The longer sides are 2x and the shorter sides are x. SO you divide by the #s and check your work!