Answer:
C. 90ft²
Step-by-step explanation:
To find the area of a trapezoid, use the formula a = (b1 + b2)h ÷2
So when you put the numbers into the formula, you get (12 + 18) · 6 = 180 ÷ 2 = 90
Answer:
Option D → -0.28
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
Answer:
1. 6
2. 27
3. 158
4. 9
5. 380
6. 108
7. 48
8. 10
9. 115
10. 57
Step-by-step explanation:
The perimeter is:
P = 2x + 2y = 80
The area is:
A = x * y
The area as a function of a variable is:
A (x) = x * (40-x)
Rewriting we have:
A (x) = 40x-x ^ 2
We derive the function:
A '(x) = 40-2x
We equal zero and clear x:
40-2x = 0
2x = 40
x = 40/2
x = 20 feet
The other dimension is:
y = 40 - x
y = 40 - 20
y = 20 feet
The area will be:
A = x * y
A = 20 * 20
A = 400 feet ^ 2
Answer:
The dimensions are:
x = 20 feet
y = 20 feet
The area is:
A = 400 feet ^ 2