Answer:
The length of the diameter is 18 cm
Step-by-step explanation:
In this question, we are asked to calculate the diameter of a right cylinder, given that the radius and the height are equal and given the value of the surface area.
Mathematically, the surface area of a cylinder can be represented by the equation;
A = 2 π r( r + h)
since r = h, we can say h = r
Thus, the equation becomes;
A = 2 π r( r + r)
A = 2 π r(2r)
A = 4 π r^2
From the question, we can see that the value of A = 324 π
substituting this, we have;
324 π = 4 π r^2
4r^2 = 324
r^2 = 324/4
r^2 = 81
r = root of 81
r = 9 cm
The value of the diameter is two times the radius
Hence D = 2r = 2 * 9 = 18 cm
The answer would be the 3rd number line or "C"
To find the sum of the interior angles you use the formula (n-2)(180), where n is the number of sides. In this case, the number of sides is 12, so you get 1800 degrees. Then you divide by number of angles which is 12. So your answer is 150 degrees.
