STEP 1: find side $ a $
To find side $ a $ use formula:
After substituting $ A = 8 $ we have:
$$ A = a^2 $$ $$ a^2 = 8 $$ $$ a = \sqrt{ 8 } $$ $$ a = 2 \sqrt{ 2 } $$STEP 2: find incircle radius $ r $
To find incircle radius $ r $ use formula:
$$ r = 2 \cdot a $$After substituting $ a = 2 \sqrt{ 2 } $ we have:
$$ r = 2 \cdot 2 \sqrt{ 2 } $$ $$ r = 4 \sqrt{ 2 } $$