how to show that $\int_{C_\epsilon}f(z)dz=\int_Tf(z)dz$

Question

$\omega$ is an open subset of complex numbers and let $T\subset\omega$ be a triangle whose interior is also contained in $\omega$. f is a function holomorphic in $\omega$ except possibly at a point a inside T. Then let $C_\epsilon$ be a circle centered at the point b with radius $\epsilon$. Let $\epsilon$ small enough so that the circle lies inside the interior of T. I am just wondering how to show that $\int_{C_\epsilon}f(z)dz=\int_Tf(z)dz$?