To find side $ a $ use formula:
$$ d_1^2 + d_2^2 = 4 \cdot a^2 $$After substituting $ d_1 = 32 $ and $ d_2 = 24 $ we have:
$$ 32^2 + 24^2 = 4 \cdot a^2 $$ $$ 1024 + 576 = 4 \cdot a^2 $$ $$ 4 \cdot a^2 = 1600 $$ $$ a^2 = \frac{ 1600 }{ 4 } $$ $$ a^2 = 400 $$ $$ a = \sqrt{ 400 } $$$$ a = 20 $$