beberapa pernyataan berikut:

1.nilai y=26° salah.

2.besar AOG=45° benar.

3.besar COE=42° salah.

4.besar DOF=102° benar.

Pembahasan :

Garis DC garis pelurus. sudut berjumlah 180⁰.

57⁰ + 78⁰ + AOG = 180⁰

AOG = 180-57-78 = 45⁰

garis AB garis pelurus.

AOG + 78 + 3y = 180

45 + 78 + 3y = 180

3y = 180 - 45 - 78

3y = 57

y = 19⁰

garis FG garis pelurus.

78 + 3y + BOF = 180

78 + 57 + BOF = 180

BOF = 45⁰

garis AB garis pelurus.

57 + COE + 30 + BOF = 180

57 + COE + 30 + 45 = 180

COE = 180 -30-45-57

= 48⁰

DOF = BOF + 3y

= 45 + 57

= 102⁰