Tan betha=16/12, betha berada dikuadran IV, nilai (sin B) pangkat 2 + (cos B) pangkat 2=...

cos(b-b) = cos²b + sin²b
cos 0 = cos²b + sin²b
1 = sin²b + cos² b

Bab Trigonometri
Matematika SMA Kelas X

tan B =16/12 = y/x

r = √(x² + y²)
r = √(12² + 16²)
r = √(144 + 256)
r = √400
r = 20

(sin B)² + (cos B)²
= (y/r)² + (x/r)²
= (16/20)² + (12/20)²
= 256/400 + 144/400
= 400/400
= 1

atau

(sin B)² + (cos B)² = 1 → identitas trigonometri, berapapun besar sudutnya