Answer:
16 ft
Step-by-step explanation:
Slant Height=sqrt(Radius^2+Height^2)
Height=sqrt(20^2-12^2)=sqrt(256)=16 ft
For the numbers in
form, convert to polar form:

By DeMoivre's theorem,





For the numbers already in polar form, DeMoivre's theorem can be applied directly:


At second glance, I think the 2s in the last two numbers should also be getting raised to the 3rd and 4th powers:


~ Simplifying
-2(7x + -5) = -14x + 10
~ Reorder the terms:
-2(-5 + 7x) = -14x + 10
(-5 * -2 + 7x * -2) = -14x + 10
(10 + -14x) = -14x + 10
~ Reorder the terms:
10 + -14x = 10 + -14x
~ Add '-10' to each side of the equation.
10 + -10 + -14x = 10 + -10 + -14x
~ Combine like terms: 10 + -10 = 0
0 + -14x = 10 + -10 + -14x
-14x = 10 + -10 + -14x
~ Combine like terms: 10 + -10 = 0
-14x = 0 + -14x
-14x = -14x
~ Add '14x' to each side of the equation.
-14x + 14x = -14x + 14x
~ Combine like terms: -14x + 14x = 0
0 = -14x + 14x
~ Combine like terms: -14x + 14x = 0
0 = 0
~ Solving
0 = 0
~ This equation is an identity, all real numbers are solutions.
I think, I'd go with A) Always true. As 2 points is always the line. If you add third one, it will be collinear.