MTK tolong jawab yaaaaaa!!

7. 7x+5x= 180°
12x=180°
x=180/12= 15°
<ABD=7x15=105°
<CBD=5x15=75°
8. 2y+102=180
2y=180-102
2y=78
y=78/2=39
9. a=180-60=120, b=60, c=a=120
10. siku2=90, sudut lurus=180, sudut lancip <90, sudut tumpul= >90, sudut reflek=360