Find Outer Surface Area of Cylindrical Hole Ring

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A cylindrical hole is put through a ball of radius a (>b) to form a ring. I am trying to find the outer surface area of the ring. I know i am supposed to parametrise the ring in some way, as we are learning about parametrizing surfaces. But I don't really know how to go about solving this problem.
 
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oh the radius of the cylindrical hole is 'b'

(i already know the numerical answer, i just am having problems starting the problem)
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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