tolong kerjain no.1-3

1). nilai x
180°= 3x +60°
180°-60° =3x
120° =3x
40° = x

2). nilai x
180= 2x + 40 +30
180 =2x +70
180-70 = 2x
110 =2x
55= x

3) sudut lancip
sudut tumpul