Tolong yg no 4 donk ama cara juga ya..

» Gunakan aturan sinus

a/sin A = c/sin C
12/sin30 = c/sin 45
12 * 2/1 = c/sin 45
c = 24 * 1/2 akar2
c = 12 akar2 cm

c^2 = a^2 + b^2 - 2ab cos C
c^2 = (12)^2 + (8)^2 - 2 . 12 . 8 cos 45°
c^2 = 144 + 64 - 2 . 96 . 1/2 √2
c^2 = 208 - 96√2
c = √(208 - 96√2)
c = √(16 (13 - 6√2))
c = 4 √(13 - 6√2) cm