Trapezoid
it has four sides and 1 set of parallel lines
We have a bunch of rectangles making up the lateral sides of this figure. They have side length 12 and height 13.
So the area of one rectangle is 12 x 13 = 156.
We have 6 of these rectangles, so our lateral area is 6(156) = 936.
The total surface area requires that we include the area of the base. To find the area of a regular polygon we take half of the product of the apothem and perimeter.
A = (1/2)*a*p
The apothem is given to be 10.39,
and the perimeter is fairly easy to calculate:
With the side length being 12, the perimeter is then 6(12) = 72.
So then the area of our base is (1/2)*10.39*72 = 374.04
So then the total surface area is the (base area) + (lateral area),
374.04 + 936 = 1310.04
The change in value over 4 years is
$22,000 - 30,000 = -$8,000
so the average change in value per year is
-8000/4 = -2000
Answer:
Length: 6 m
Width: 4 m
Step-by-step explanation:
Area: 24 
Width: 2L - 8 m
Length: ?
Formula: A = W * L
Replace the variables:
24 = (2L - 8) * L
24 = 2
- 8L
0 = 2
- 8L - 24
or
2
- 8L - 24 = 0
Solve; if you don't know how to solve it using this method, let me know. It's the expression 
1. 
2. 
3. 
4. 
5. (L-6) (2L+4)
6. L-6 = 0 AND 2L+4 = 0
L - 6 =0
L = 6
---------------------------------
2L = -4
L = 
L = -2
Since the length cannot be negative, the only real value is 6.
Area: 24 
Width: 2L - 8 m
Length: 6 m
Calculate width:
W = 2L - 8
W = 2(6) - 8
W = 12 - 8
W = 4 m
25% or 1/4
1/2 × 1/2 = 1/4