ada yg bisa jawab klw bisa jawab saya kasih yg terbaik buat kalian

A.
5x + 4x = 180° >>>> sudut pelurus
9x = 180°
x = 20°

B.
A3 = 5x = 5 (20)° = 100°
C4 = 4x = 4 (20)° = 80°

C.
A1 + B2 + C1
(100 + 80 + 100)°
280°