Answer:
Step-by-step explanation:
Given - The circumference of the ellipse approximated by 
where 2a and 2b are the lengths of 2 the axes of the ellipse.
To find - Which equation is the result of solving the formula of the circumference for b ?
Solution -
Squaring Both sides, we get
![[\frac{C}{2\pi }]^{2} = [\sqrt{\frac{a^{2} + b^{2} }{2} }]^{2} \\\frac{C^{2} }{(2\pi)^{2} } = {\frac{a^{2} + b^{2} }{2} }\\2\frac{C^{2} }{4(\pi)^{2} } = {{a^{2} + b^{2} }](https://tex.z-dn.net/?f=%5B%5Cfrac%7BC%7D%7B2%5Cpi%20%7D%5D%5E%7B2%7D%20%20%20%3D%20%20%5B%5Csqrt%7B%5Cfrac%7Ba%5E%7B2%7D%20%2B%20b%5E%7B2%7D%20%7D%7B2%7D%20%7D%5D%5E%7B2%7D%20%5C%5C%5Cfrac%7BC%5E%7B2%7D%20%7D%7B%282%5Cpi%29%5E%7B2%7D%20%20%7D%20%20%20%3D%20%20%7B%5Cfrac%7Ba%5E%7B2%7D%20%2B%20b%5E%7B2%7D%20%7D%7B2%7D%20%7D%5C%5C2%5Cfrac%7BC%5E%7B2%7D%20%7D%7B4%28%5Cpi%29%5E%7B2%7D%20%20%7D%20%20%20%3D%20%20%7B%7Ba%5E%7B2%7D%20%2B%20b%5E%7B2%7D%20%7D)
∴ we get
Let's turn this sentence into an equation:
8n = -n + 36
Then solve:
9n = 36 => n=4
The perimeter of the square is calculated through the equation,
4x = P
where P is the perimeter and x is the measure of the sides.
When P is 32 units then,
32 units = 4(x)
x = 8 inches
This 8 inches is the diameter of the cylinder formed by the rotation.
The circumference of the base is calculated through,
C = 2πr = πD
Substituting the known values,
C = π(8 units) = <em>8π units
</em><em></em>When π is equal to 3.14, we solve for the numerical value of the cylinder as follows,
<em> C = 8(3.14) = 25.12 units
</em><em></em>Thus, the figure formed is a cylinder with base circumference equal to 25 units. The answer is the third choice. <em>
</em>
I do believe the answer is D
