Verifying formula as a result of stokes theorem

The first part of the question states prove, $\displaystyle \oint_{c} r \wedge dr= 2 \iint_{s} ds$ This I have done using stokes theorem, however stuck on the next part which states, verify this forumla is also applicable when s has a mild singularity, by evaluating both sides of the equation for the case when s is the cone,$\displaystyle {(x,y,z): (1-z)^{2}=x^{2}+y^{2}, x^{2}+y^{2} \leq 1, z\geq0}$ and c is the circle $\displaystyle x^{2}+y^{2}=1$ in the xy plane.Just struggling to know what is what from the information we have to use it in the question, many thanks in advance.