Jika DG//EH maka besar ECF adalah

Kelas 8 Matematika
Bab Garis dan Sudut

sudut ABD + sudut BCH = 180°
5x + 30° + 2x + 10° = 180°
7x = 180° - 40°
x = 140°/7
x = 20°

sudut ECF
= sudut BCH
= 2x + 10°
= 2 . 20° + 10°
= 40° + 10°
= 50°

ditanyakan=sudut ECF..?

jawab

sudut ABD + sudut BCH = 180°
5x+30°+2x+10° = 180°
5x+2x+30°+10° = 180°
7x+40° = 180°
7x=180° - 40°
7x=140°
x=140° / 7
x=20°

sudut ECF=sudut BCH
=2x+10°
=2(20°)+10°
=40°+10°
=50°

semoga membantu