jawablah pertanyaan no. 9, 10, dan 11 pada gambar di bawah ini!!! dwngan cara jlannya!!!.....

<A + <B + <C = 180
120 + 30 + <C = 180
<C = 30
BC/sin A = BA/sin C
36/sin 120 = BA/sin 30
36/(√3/2) = BA/(1/2)
BA(√3/2) = 36 × 1/2
BA = 18 ÷ √3/2
BA = 18 × 2/√3
BA = 36/√3
BA = 36√3/3
BA = 12√3
L = ½.BA.BC sin B
L = ½(12√3)(36) sin 30
L = (6√3)(36)(1/2)
L = 108√3

10. radian = panjang busur / jari 2
radian = 14/7 = 2
jadi 2 radian

11. sin A = -1/4, karena tan a positif maka A di kuadran 3
sisi depan 1
sisi miring 4
sisi samping √15
cos A = -√15/4 = -¼√15