Answer:

Step-by-step explanation:
The formula for the surface area of a cylinder is:

And we want to solve for the height h.
First, subtract
from both sides. This yields:

Now, divide both sides by
. This yields:

And we're done!
The angle here is an acute angle at ground level. Then the side adjacent to this angle is 126 feet. The opp. side is the tower, 111 feet tall.
Then
tan theta = opp / adj = 111 / 126. Using the inverse tangent function, we find that the measure of the angle is 0.722 radian or 41 degrees (to the nearest degree).
I and III seem to be correct, II doesn't because, for example, if x = w = z = t = 70 and y = u = 40, then all three pairs of vertical angles in the figure have equal measure and the given condition x + y = u + w stands. But it means y is not equal to w.
We can simplify across between the 5 and the 50 and also between the 42 and the 3.
18. equivalent
16x5 does equal 10x8
19. equivalent
13-0 does equal 0
20. Not equivalent
12-2 doesn’t not equal 7-3
For all three of these equations you have to use PEMDAS (systems of equations) so first you solve everything that’s in parentheses, then any exponents, followed by multiplication,division,addition, and lastly subtraction. You MUST follow that order to get the correct answer.