From the points given we know that the rectangle is 3 points wide and 2 points tall. If we rotate it
around the x axis then we will receive the lying cyllinder which will be 3 points tall and 2 points wide (so its radius is 2/2 = 1 point). Now we can find the surface area of the cyllinder using appropriate formula:
Answer:
Because it is a rectangle, the area is expressed as A = xy, or length times width.
Because it is next to the river, he only needs to fence three sides, so F = x + 2y.
Knowing the amount of fencing available is 7500m, we get:
7500 = x + 2y solve for x
x = 7500 - 2y substitute into the area equation
A = (7500 - 2y)y distribute
A = -2y2 +7500y
You can see that this is a parabola which opens down, meaning that the point of maximum area will be at the vertex, y = -b/2a = -7500/[2(-2)] = 1875
x = 7500 - 2(1875) = 3750
A = 3750(1875) = 7,031,250 m2
Step-by-step explanation:
Answer:
628
Step-by-step explanation:
area of full circle is pir^ 2
divide by 2 for semicircle
