tlong dijawab secepatnya bang,,,,sama carnya jga

a. x = 40°
    y = 180° - 40° = 140°
    z = y = 140°
b. a = 180° - (180°-50°-37°) - (180°-50°-73°)
       = 30°
c. a = 180° - (180°-45°-(180°-110°))
       = 115°