Answer:
324 pi . and 36 pi
Step-by-step explanation:
Area is pi r squared, so 18x18 is 324, times pi which is 324 pi
Circumference is 2 pi r, which is 2 times 18 which is 36, times pi which is 36 pi
:D
Answer:

Step-by-step explanation:
The base of the pyramid we need to study is a hexagon.
Let's look at the attached image of an hexagon to understand how we are going to find the area of this figure.
Notice that an hexagon is the combination of 6 exactly equal equilateral triangles in our case of size "2x" (notice that the "radius" of the hexagon is given as "2x")
Therefore the area of the hexagon is going to be 6 times the area of one of those equilateral triangles.
We know the area of a triangle is the product of its base times its height, divided by 2: 
We notice that the triangle's height is exactly what is called the "apothem" of the hexagon (depicted in green in our figure) which measures
, so replacing this value in the formula above for the area of one of the triangles:

Then we multiply this area times 6 to get the total area of the hexagon (6 of these triangles):
Area of hexagon = 
which is the last option given in the list.
Answer:
C) 0 ≤ x ≤ 25
Step-by-step explanation:
We are supposed to find a reasonable constraint so that the function is at least 300 i.e. the value of x at which f(x) is greater or equal to 300
A)x ≥ 0
Refer the graph
At x = 0
f(x)=300
On increasing the value of x , f(x) increases but at x = 12 it starts decreasing
So, x ≥ 0 can also have f(x)<300
So, Option A is wrong
B)−5 ≤ x ≤ 30
At x = -5
f(x) = 100
So, Option B is wrong since we require f(x) is greater or equal to 300
c)0 ≤ x ≤ 25
At x = 0
f(x)=300
At x = 12 , it starts decreasing
At x = 25
f(x)=300
So, The value of f(x) is at least 300 when 0 ≤ x ≤ 25
D)All real numbers
At x = 30
f(x)=0
But we require f(x) greater or equal to 300
Hence Option C is true
The perimeter of these can be found by adding length and width and then multiplying by two.
Rectangle A: (with all of the variables already doubled)
2x + 16 + 2x - 2
2x + 2x + 16 - 2
4x + 14
So rectangle A's perimeter is 4x + 14.
Rectangle B: (Still with all the variables already doubled)
8x + 10 + 6x - 4
8x + 6x + 10 - 4
14x + 6
So rectangle B's perimeter is 14x + 6
And now to subtract the two.
(7x + 3) - (4x + 14)
14x + 6 - 4x - 14
14x - 4x + 6 - 14
10x - 8
So it would be C.
Answer: 11/20
55/100 simplified is 11/20