tolong dong no 1-3 pake cara ya

1. Dik :
a = 12 cm
c = 10 cm
sudut B = 45

L = ½ x a x c x sin 45
L = ½ x 12 x 10 x 1/2√2
L = 1/4 x 120√2
L = 30√2 cm²

2. Dik :
a = 5 cm
b = 7 cm
sudut C = 30

L = ½ x a x b x sin 30
L = ½ x 5 x 7 x 1/2
L = 1/4 x 35
L = 8.45 cm²