How do you find terminal velocity of a falling object?

I think its supposed to be something like this

Use the terminal velocity formula, v = the square root of ((2*m*g)/(ρ*A*C)).m = mass of the falling object.
g = the acceleration due to gravity.
p = the density of the fluid the object is falling through.
a = the projected area of the object.
c = the drag coefficient.
My grandfather is a whiz at math so helped me figure it out