[tex]a)180 - 120 = 60 \\ \beta = 60 \\ 180 - 40 - 60 = 80 \\ \gamma = 80 \\ b) \alpha = 50 \\ \beta = 80 \\ c)180 - 90 = 90 \\ 90 \div 2 = 45 \\ \alpha = 45 \: \beta = 45 \\ d) \alpha = 40 \\ 360 - 80 = 280 \\ 280 \div 2 = 140 \\ \beta = 140 \: \: \: \: \gamma = 140 \\ e) \beta = 60 \\ 360 - 120 = 240 \\ 240 \div 2 = 120 \\ \alpha = 120[/tex]
