STEP 1: find side $ a $

To find side $ a $ use formula:

$$ r = \dfrac{ \sqrt{ 3 } \cdot a }{ 2 } $$

After substituting $r = 3.55\, \text{cm}$ we have:

$$ 3.55\, \text{cm} = \dfrac{ \sqrt{ 3 } \cdot a }{ 2 } $$ $$ \sqrt{ 3 } \cdot a = 3.55\, \text{cm} \cdot 2 $$ $$ \sqrt{ 3 } \cdot a = 7.1\, \text{cm} $$ $$ a = \dfrac{ 7.1\, \text{cm} }{ \sqrt{ 3 } } $$ $$ a \approx 4.0992\, \text{cm} $$

STEP 2: find diagonal $ d $

To find diagonal $ d $ use formula:

$$ d = 2 \cdot a $$

After substituting $a = 4.0992\, \text{cm}$ we have:

$$ d = 2 \cdot 4.0992\, \text{cm} $$ $$ d \approx 8.1984\, \text{cm} $$

Hexagon Calculator