To find leg $ b $ use formula:
$$ \tan \left( \alpha \right) = \dfrac{ a }{ b } $$After substituting $ \alpha = 71^o $ and $ a = \frac{ 106 }{ 5 } $ we have:
$$ \tan( 71^o ) = \dfrac{ \frac{ 106 }{ 5 } }{ b } $$ $$ 2.9042 = \dfrac{ \frac{ 106 }{ 5 } }{ b } $$ $$ b = \dfrac{ \frac{ 106 }{ 5 } }{ 2.9042 } $$ $$ b = 7.2997 $$