Answer:
C.
Step-by-step explanation:
A has 8 lines of symmetry, because they're all the same.
B has 4 lines of symmtery because those are all the same
C has only 2 because the vertical lines are symmetrical to each other, but not to the horizontal lines
D has 10 symmetrical lines because they're all the same
F + s = 10
| f - s | = 18
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This means that:
f = 10 - s
And also that:
| f - s | = 18
(f-s)²=18²
f²- 2sf + s² = 324
But f=10-s
So...
(10-s)² - 2s(10-s) + s² = 324
(10-s)(10-s) - 20s + 2s² + s² = 324
100 - 20s + s² - 20s + 2s² + s² = 324
4s² - 40s + 100 = 324
4s² - 40s + 100 - 324 = 0
4s² - 40s - 224 = 0
1/4 * (4s² - 40s - 224) = 1/4 * 0
s² - 10s - 56 = 0
(s-14)(s+4)=0
So s can be either 14 or -4.
When s = 14, f = -4.
When s = -4, f = 14.
The formula for the volume of a cone is V = PI x r^2 x h/3
r = 1/2 the diameter. 1/2 of 8 = 4 inches.
h = height = 12 inches.
Using 3.14 for PI, the formula now becomes:
V = 3.14 x 4^2 x 12/3
V = 3.14 x 16 x 4
V = 200.96 cubic inches.
You do not say if the answer needs to be rounded, so round the answer as needed.