Tolong banget dong yang bida jawab.. No berapa aja boleh
Matematika
halidaa
Pertanyaan
Tolong banget dong yang bida jawab.. No berapa aja boleh
1 Jawaban
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1. Jawaban whongaliem
1) AB/sin C = AC / sin B
10 / sin C = 15 / sin 30°
10 / sin C = 15 / (1/2)
15 .sin C = 10 . 1/2
15 sin C = 5
sin C = 5/15
sin C = 1/3
sin² C + cos² C = 1
(1/3)² + cos² C = 1
1/9 + cos² C = 1
cos² C = 1 - 1/9
cos² C = 8/9
cos C = √(8/9)
cos C = (2/3)√2
3) luas = 1/2 x AB x BC x sin B
= 1/2 x 6 x 10 x sin 30°
= 1/2 x 6 x 10 x 1/2
= 3 x 5
= 15 cm²
4) luas = 1/2 x BC x AC x sin C
= 1/2 x 10 x 40 x sin 120°
= 1/2 x 10 x 40 x 1/2√3
= 100√3 xm²