Derive Formula for Surface Area of Black Hole

[Werg22]

Homework Statement

Einstein's theory of general relativity is relativistic model of gravity. "Relativistic" means it involves the speed of light, c; "gravity" means it involves Newton's constant, G. Use dimensional analysis to derive a formula for the surface area, A, of a black hole of mass M, up to a dimensionless proportionality constant.

Homework Equations

N/A

The Attempt at a Solution

I have little idea of how to tackle this question. Any sort of help would be appreciable.

 

[mgb_phys]

Not sure I follow the question.
The only meaningful surface area I can think of for a black hole is the area of a sphere with the Schwarzschild radius.