I'll do the first three problems to get you started. If you still need help with the fourth question, then please let me know and I'll update my solution.
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Problem 1
Answer: 200 square inches
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Work Shown:
The pentagon can be divided into five triangles as shown in figure 1 (attached image below). You start at the center of the pentagon and extend to each vertex. Each of these triangles are congruent, or the same. Each copy is a rotated version of another.
Each triangle has a base of 10, and a height of 8
A = area of one triangle
A = (1/2)*base*height
A = 0.5*10*8
A = 5*8
A = 40 square inches
There are n = 5 triangles, so the total area is therefore n*A = 5*40 = 200
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Problem 2
Answer: 30 square cm
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Work Shown:
base = 6 is the horizontal component
height = 5 cm is the vertical component
rule: the base and height are always perpendicular to one another
the area of the parallelogram is simply the product of base and height
area of parallelogram = base times height
A = B*H
A = 6*5
A = 30 square cm
The 7 cm isn't used at all. It's likely put in there to distract.
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Problem 3
Answer: 22 square meters
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Work Shown:
Have a look at figure 2 shown below. I divide up the original figure (which looks somewhat like an odd shoe of sorts) into a rectangle and a triangle.
The rectangle is 9 by 2, so it has area 9*2 = 18
The triangle has a base of 2 and height of 4 (these values are explained in the diagram I provided). So the triangle's area is 0.5*B*H = 0.5*2*4 = 4
The total area is therefore
(area of rectangle) + (area of triangle) = 18+4 = 22