Berdasarkan gambar diatas,hitunglah nilai x dan besar sudut BCF

a. nilai x
ABC = FCG (karena sudut sehadap)
3x - 45 = x + 23
2x° = 68°
x = 34°

b. BFC
BFC + FCG = 180° (sudut pelurus)
BFC + (x + 23)° = 180°
BFC + (34+23)° = 180°
BFC + 57 = 180
BFC = 180° - 57° = 123°