Tolong bantu jawab cm yg dicentang saja, terima kasih​

Jawaban:

1. Maaf, ngga bisa:(

2. D. 26,38°

3. B. 4√5

Penjelasan dengan langkah-langkah:

2. Cos C = (AC² + BC² – AB²)/2.AC.BC

Cos C = (8² + 12² – 6²)/(2.8.12)

Cos C = 172/192

Cos C = 0,89583

C = 26,38°

3. BC = AB = 5

BT = TC – BC

= 8 – 5

= 3

Pada ∆ATB siku-siku di T:

cos ∠ABT = BT/AB = 3/5, maka

cos ∠ABC = cos (180 – ∠ABT)°

= –cos ∠ABT

= –3/5

AC² = AB² + BC² – 2AB . BC cos ∠ABC

= 5² + 5² – 2 . 5 . 5 . (-3/5)

= 50 + 30

= 80

AC = √80

= 4√5 ~ 8,94 cm