Answer
$91$
Work Step by Step
Using the given general term, $
a_n=n^2
,$ then,
\begin{array}{l}
a_1=(1)^2\\
a_1=1
,\\\\
a_2=(2)^2\\
a_2=4
,\\\\
a_3=(3)^2\\
a_3=9
,\\\\
a_4=(4)^2\\
a_4=16
,\\\\
a_5=(5)^2\\
a_5=25
,\\\\
a_6=(6)^2\\
a_6=36
.\end{array}
Hence, $
S_6=1+4+9+16+25+36
=
91
.$
