tolong di jawab + cara

1. 2a + 3a = 90°
5a = 90°
a = 90/5
a = 18
2a = 2.18= 36
3a = 3.18= 54


46+a+29+5a+15=180
90+6a = 180
6a = 180-90
6a = 90
a = 90:6
a = 15


a+29=15+29=44
5a+15=5.15+15=75+15=90