Mohon dijawab menggunakan cara
Jawab:
Penjelasan dengan langkah-langkah:
segitiga
trigonometri
aturan sin
luas
__
soal
Δ ABC , <B = 45,. <C = 30
<A = 180 – B -C
<A = 105
b/sin B = c/sin C
c = b. sin C/ sin B
c = 8. sin 30 / sin 45
c = 8 (1/2) / (1/2 √2)
c = 8/√2
c = 4√2
Luas ABC = 1/2 b c sin A
L = 1/2. 8 . 4√2 . sin (105)
L = 16√2. { sin(60+45)}
L = 16√2. {sin 60 cos 45 + cos 60 sin 45}
L = 16√2. {¹/₂ √3 . ¹/₂ √2 + ¹/₂ . ¹/₂ √2}
L = 16√2. {¹/₄ √ 6 + √2}
L = 4√12 + 16(2)
L = 4. (2√3) + 32
L = 8√3 + 32