bantu jawabin ya kak No 27&29. pliss

Mapel : Matematika
Kelas : X SMA
Bab : Trigonometri

Pembahasan :
27|| Aturan Cosinus

BC² = AB² + AC² - 2(AB)(AC) Cos A
BC² = 8² + 5² - 2(8)(5) Cos 60
BC² = 64 + 25 - 40
BC² = 49
BC = √49
BC = 7 cm

Aturan Cosinus
Cos < ACB = (AC² + BC² - AB²)/2(AC)(BC)
Cos < ACB = (5² + 7² - 8²)/70
Cos < ACB = (25 + 49 - 64)/70
Cos < ACB = 10/70
Cos < ACB = 1/7

29|| Aturan Sinus
PR/Sin Q = PQ/Sin R
(4√2) . Sin R = 4 . Sin Q
(4√2) . Sin 30° = 4Sin Q
4Sin Q = 2√2
Sin Q = 1/2 √2
Q = 45°

< P = 180° - (30 + 45)°
< P = 180° - 75°
< P = 105°