To find side $ a $ use formula:
$$ d_1^2 + d_2^2 = 4 \cdot a^2 $$After substituting $ d_1 = 32 $ and $ d_2 = 12 $ we have:
$$ 32^2 + 12^2 = 4 \cdot a^2 $$ $$ 1024 + 144 = 4 \cdot a^2 $$ $$ 4 \cdot a^2 = 1168 $$ $$ a^2 = \frac{ 1168 }{ 4 } $$ $$ a^2 = 292 $$ $$ a = \sqrt{ 292 } $$$$ a = 2 \sqrt{ 73 } $$