tolong no 13 besok di kumpul pakai caranya

4x+4+3x+8+5x=180°
12x+12=180°
12x=180-12
12x = 168
x=168 ÷ 12
x= 14

Sudut CED = 3x+8= 3×14+8=50° (A)

(4x + 4) + (3x + 8) + 5x = 180
12x + 12 = 180
12x = 168
x = 14

3x + 8 = 3(14) + 8 = 50