Nomor 4 ya, dijawab pakai cara

sin @ = sin 60°
b/a = 1/2 √3
b = 1/2 √3 a = 1/2 √3 . 6 = 3√3 cm

Cos @ = cos 60°
c/a = 1/2
c = 1/2 a = 1/2 . 6 = 3 cm