1. 1 Press Ctrl-A ©G Dear2008 – Not to be sold/Free to use Cosine Ratio Stage 4 Year 9

2. 2 Hypotenuse Adjacent Adjacent Click Cos θ = AdjacentHypotenuse θ θ Trig Ratios

3. 3 13 12 Cos θ = AdjacentHypotenuseP QR 5 Cos P = 5 13 Cos R = 12 13 Trig Ratios

4. 4 26 Cos θ = AdjacentHypotenuseP Q R 10 Cos A = 5 13 13 12 A B 5 C Cos P = 10 26 = 5 13 22222222 Cos C = 12 13 Cos R = 24 26 = 12 13 22222222 24 Trig Ratios

5. 5 6 60 o Cos θ = AdjacentHypotenusem cos 60 o = m 6 6x x6 m = 6 x cos 60 o = 3 Use your Calculator! Trig Ratios

6. 6 10 30 o d cos 30 o = d 10 10x x10 10 x cos 30 o ≈ 8.66 Use your Calculator! d = Trig Ratios Cos θ = AdjacentHypotenuse

7. 7 k 50 o 6 cos 50 o = 6 k kx xk 6 = k x cos 50 o ≈ 9.33 Use your Calculator!  Sin 50 o  Sin 50 o k = 6  cos 50 o Trig Ratios Cos θ = AdjacentHypotenuse

8. 8 12 zozozozo 6 cos z o = 6 12 zo =zo =zo =zo = cos -1 ( ) Use your Calculator! = 60 o 612 Trig Ratios Cos θ = AdjacentHypotenuse

9. 9 15 momomomo 5 cos m o = 5 15 mo =mo =mo =mo = cos -1 ( ) Use your Calculator! ≈ 71 o 515 To nearest whole degree Trig Ratios Cos θ = AdjacentHypotenuse

10. 10 S Some O Old H Hags ------ C Can A Always H Hide ------ T Their O Old A Age S Sin O Opposite H Hypotenuse ------ C Cos A Adjacent H Hypotenuse ------ T Tan O Opposite A Adjacent