$(4+4+4pts)$ Consider the following rectangular signal: $x(t)=\{\begin{array}{cc}1,& -1t1\\ 0,& \text{o}\text{t}\text{h}\text{e}\text{r}\text{w}\text{i}\text{s}\text{e}& \end{array}$

$($a$)$ Find $x(t)**x(t).$

$($b$)$ Find the Fourier transform of $($a$).$

$($c$)$ Evaluate the following integral: ${\displaystyle \underset{-}{\overset{}{}}}\frac{si{n}^{2}t}{t^2}dt$