36. aturan cos pada segitiga: a² = b² + c² - 2.b.c.cos A 9² = 7² + 8² - 2.7.8.cos A 81 = 49+64 - 112cos A cos A = 32/112 cos A = 2/7................opsi A
37. sama kayak 36 aturan cos pada segitiga: a² = b² + c² - 2.b.c.cos A 7² = 8² + 5² - 2.8.5.cos A 49 = 64+25 - 80cos A cos A = 40/80 cos A = 1/2 ∠A = arccos (1/2) ∠A = 60°................opsi C
36. aturan cos pada segitiga:
a² = b² + c² - 2.b.c.cos A
9² = 7² + 8² - 2.7.8.cos A
81 = 49+64 - 112cos A
cos A = 32/112
cos A = 2/7................opsi A
37. sama kayak 36
aturan cos pada segitiga:
a² = b² + c² - 2.b.c.cos A
7² = 8² + 5² - 2.8.5.cos A
49 = 64+25 - 80cos A
cos A = 40/80
cos A = 1/2
∠A = arccos (1/2)
∠A = 60°................opsi C