Answer:
[tex] \boxed{ \bold{ \huge{ \boxed{ \sf{128°}}}}}[/tex]
Step-by-step explanation:
Sum of angles of triangle add up to 180°
Let the third angle be x
Create an equation and solve for x
[tex] \sf{x + 12° + 40° = 180°}[/tex]
[tex] \dashrightarrow{ \sf{x + 52° = 180°}}[/tex]
[tex] \dashrightarrow{ \sf{x = 180° - 52°}}[/tex]
[tex] \dashrightarrow{ \boxed{\sf{x = 128°}}}[/tex]
Hope I helped!
Best regards! :D
