STEP 1: find angle $ \alpha $
To find angle $ \alpha $ use formula:
$$ \alpha + \beta = 90^o $$After substituting $ \beta = 55^o $ we have:
$$ \alpha + 55^o = 90^o $$ $$ \alpha = 90^o - 55^o $$ $$ \alpha = 35^o $$STEP 2:
Internal error: There are more than 1 unknown parameter.