3)

4)

Explanation:
3)
The regular hexagon can be seen as consisting of 6 identical triangles, so its area is equal to six times the area of one triangle:

The area of one triangle can be written as:

where:
is the base of the triangle
is the height
Substituting,

And so, the area of the regular hexagon is:

4)
Here we have a complex figure consisting of several regular figures.
We observe that the figure consists of 2 parallelograms, on top and on bottom, so the total area of the figure is the sum of the areas of the two parallelograms:

where
is the area of one parallelogram, which is given by

where:
b = 7 yd is the base of the parallelogram
h = 3 yd is the height of the parallelogram
Therefore, the area of the parallelogram is

And therefore, the area of the figure is:
