$\left| \begin{matrix}
{{1}^{2}} & {{2}^{2}} & {{3}^{2}} & {{4}^{2}} \\
{{2}^{2}} & {{3}^{2}} & {{4}^{2}} & {{5}^{2}} \\
{{3}^{2}} & {{4}^{2}} & {{5}^{2}} & {{6}^{2}} \\
{{4}^{2}} & {{5}^{2}} & {{6}^{2}} & {{7}^{2}} \\
\end{matrix} \right|$
Let $\vartriangle =\left| \begin{matrix}
{{1}^{2}} & {{2}^{2}} & {{3}^{2}} & {{4}^{2}} \\
{{2}^{2}} & {{3}^{2}} & {{4}^{2}} & {{5}^{2}} \\
{{3}^{2}} & {{4}^{2}} & {{5}^{2}} & {{6}^{2}} \\
{{4}^{2}} & {{5}^{2}} & {{6}^{2}} & {{7}^{2}} \\
\end{matrix} \right|$
Now we have to apply the column operation ${{C}_{3}}\to {{C}_{3}}-{{C}_{2}}$and ${{C}_{4}}\to {{C}_{4}}-{{C}_{1}}$, then we get,
$\vartriangle =\left| \begin{matrix}
{{1}^{2}} & {{2}^{2}} & {{3}^{2}}-{{2}^{2}} & {{4}^{2}}-{{1}^{2}} \\
{{2}^{2}} & {{3}^{2}} & {{4}^{2}}-{{3}^{2}} & {{5}^{2}}-{{2}^{2}} \\
{{3}^{2}} & {{4}^{2}} & {{5}^{2}}-{{4}^{2}} & {{6}^{2}}-{{3}^{2}} \\
{{4}^{2}} & {{5}^{2}} & {{6}^{2}}-{{5}^{2}} & {{7}^{2}}-{{4}^{2}} \\
\end{matrix} \right|$
$\vartriangle =\left| \begin{matrix}
{{1}^{2}} & {{2}^{2}} & 5 & 5 \\
{{2}^{2}} & {{3}^{2}} & 7 & 7 \\
{{3}^{2}} & {{4}^{2}} & 9 & 9 \\
{{4}^{2}} & {{5}^{2}} & 11 & 11 \\
\end{matrix} \right|$
As, ${{C}_{3}}={{C}_{4}}$so, the determinant is zero.