To find angle $ \alpha $ use formula:
$$ \sin \left( \alpha \right) = \dfrac{ h }{ a } $$After substituting $ h = \frac{ 179 }{ 100 } $ and $ a = \frac{ 181 }{ 100 } $ we have:
$$ \sin \left( \alpha \right) = \dfrac{ \frac{ 179 }{ 100 } }{ \frac{ 181 }{ 100 } } $$ $$ \sin \left( \alpha \right) = \frac{ 179 }{ 181 } $$ $$ \alpha = \arcsin\left( \frac{ 179 }{ 181 } \right) $$ $$ \alpha = 81.4746^o $$