Consider the graph of the function $g(x)$:

The graph from $x=2$ to $x=6$ is a semicircle. Evaluate the following integrals by interpreting them in terms of areas:

(a) $\displaystyle \int_{0}^{\,2} {g(x)}\,dx =$

(b) $\displaystyle \int_{2}^{\,6} {g(x)}\,dx =$

(c) $\displaystyle \int_{0}^{\,7} {g(x)}\,dx =$