Answer:
x = 500 yd
y = 250 yd
A(max) = 125000 yd²
Step-by-step explanation:
Let´s call x the side parallel to the stream ( only one side to be fenced )
y the other side of the rectangular area
Then the perimeter of the rectangle is p = 2*x + 2* y ( but only 1 x will be fenced)
p = x + 2*y
1000 = x + 2 * y ⇒ y = (1000 - x )/ 2
And A(r) = x * y
Are as fuction of x
A(x) = x * ( 1000 - x ) / 2
A(x) = 1000*x / 2 - x² / 2
A´(x) = 500 - 2*x/2
A´(x) = 0 500 - x = 0
x = 500 yd
To find out if this value will bring function A to a maximum value we get the second derivative
C´´(x) = -1 C´´(x) < 0 then efectevly we got a maximum at x = 500
The side y = ( 1000 - x ) / 2
y = 500/ 2
y = 250 yd
A(max) = 250 * 500
A(max) = 125000 yd²
Answer:Area = 492.4 m²
Explanation:The area of the triangle can be calculated using the side-angle-side method as follows:
Area = 0.5 * first side * second side * sin(angle included between these two sides)
This rule is illustrated in the attached image.
Now, we have:
AB = 40 m
BC = 25 m
angle B which is the angle included between AB and BC = 80 degrees
The given angle is included between the two given sides, therefore, we can apply the above rule to get the area.
Area of triangle = 0.5*40*25*sin(80)
Area of triangle = 492.4 m²
Hope this helps :)
Rectangle on the left = 3 × 4 = 12
Rectangle in the middle = 3 × 2 = 6
Rectangle on the right = 4 × 3 = 12
Add:
12 + 6 + 12 = 30
Answer = 30
Hope this helped☺☺