\[\boxed{\mathbf{32}.}\]
\[\textbf{а)}\ На\ отрезке\ \lbrack 0;2\rbrack\]
\[y = x \geq 0:\]
\[\int_{0}^{2}\text{xdx} = S_{\text{AOB}} = \frac{2 \cdot 2}{2} = 2.\]
\[\textbf{б)}\ На\ отрезке\ \lbrack 0;2\rbrack\]
\[y = - x \leq 0:\]
\[\textbf{в)}\ На\ отрезке\ \lbrack - 4;0\rbrack\]
\[y = x \leq 0:\]
\[\int_{- 4}^{0}\text{xdx} = - S_{\text{AOB}} = - \frac{4 \cdot 4}{2} = - 8.\]
\[\textbf{г)}\ На\ отрезке\ \lbrack 0;4\rbrack\]
\[y = x \geq 0:\]
\[\int_{0}^{4}\text{xdx} = S_{\text{AOB}} = \frac{4 \cdot 4}{2} = 8.\]
\[\textbf{д)}\ На\ отрезке\ \lbrack 1;3\rbrack\]
\[y = x \leq 0:\]
\[\int_{1}^{3}{(1 - x)\text{dx}} = - S_{\text{AOB}} =\]
\[= - \frac{2 \cdot 2}{2} = - 2.\]
\[\textbf{е)}\ На\ отрезке\ \lbrack - 1;1\rbrack\]
\[y = x \geq 0:\]
\[\int_{- 1}^{1}{(2x + 2)\text{dx}} = S_{\text{AOB}} =\]
\[= \frac{2 \cdot 4}{2} = 4.\]