The formula for the area of a trapezoid is:
A = (1/2)(b_{1} + b_{2}) * h
Here's what that means: for parallelograms (including rhombuses, squares, and rectangles), the area is just base times height. But for a trapezoid, there are two bases. So, we find the average of the two bases and then multiply
that by the height. Thus, we add the two bases together, divide by two (which is the same as multiplying by 1/2), and multiply by the height.
For your problem, one base is 12 meters, the other is 8 meters, and the height is 8 meters. Now we can plug those numbers into our formula:
A = (1/2)(b_{1} + b_{2}) * h
= (1/2)(12m + 8m) * (8m)
= (1/2)(20m) * (8m)
= (10m) * (8m)
= 80 m^{2}
So, the area of your trapezoid is eighty square meters! Now you can find the area of any trapezoid!
As for the perimeter, that is always the sum of all the side lengths, no matter how many sides a shape has or how they are put together. For this trapezoid, the height isn't actually a side (I'm sure you can see this in the picture), so we don't add that
to the four sides.
P = 12m + 8m + 10m + 10m
= 20m + 20m
= 40m
The perimeter of your trapezoid is forty meters, and you can now find the perimeter of any shape!