1. adjacent = Cos o x H Cosine Ratio To find an adjacent side we need 1 side (hypotenuse) and the included angle. a = Cos ° x H a = Cos 60° x 9 a = 0.5 x 9 a = 4.5 cm a = Cos ° x H a = Cos 75° x 12 a = 0.258819045 x 12 a = 3.1 cm 9 cm 60° 12 cm 75° aa

2. Cos o = A ÷ H Cosine Ratio To find an unknown angle we need 2 sides the adjacent and the hypotenuse Cos ° = A ÷ H Cos x° = 2.5 ÷ 5 Cos x° = 0.5 Shift (Inv) (2ndF) Cos -1 0.5 = 60° Cos ° = A ÷ H Cos y° = 12 ÷ 15 Cos y° = 0.8 Shift (Inv) (2ndF) Cos -1 0.8 = 36.9° 5 cm 15 cm 12cm 2.5 cm x°x° y°y°

3. O = Sin o x H Sine Ratio To find an opposite side we need 1 side (hypotenuse) and the included angle. O = Sin ° x H O = Sin 30° x 5 O = 0.5 x 5 O = 2.5 cm O = Sin ° x H O = Sin 75° x 10 O = 0.965925826 x 10 O = 9.7cm 5 cm 30° 10 cm 75° oo

4. Sin o = O ÷ H Sine Ratio To find an unknown angle we need 2 sides the opposite and the hypotenuse Sin ° = O ÷ H Sin x° = 2.5 ÷ 5 Sin x° = 0.5 Shift (Inv) (2ndF) Sin -1 0.5 = 30° Sin ° = O ÷ H Sin y° = 12 ÷ 15 Sin y° = 0.8 Shift (Inv) (2ndF) Sin -1 0.8 = 53.1° 5 cm 15 cm 12cm 2.5 cm x°x° y°y°

5. Tan o = O ÷ A Tangent Ratio To find an unknown angle we need 2 sides the opposite and the adjacent Tan ° = O ÷ A Tan x° = 2.5 ÷ 5 Tan x ° = 0.5 Shift (Inv) (2ndF) Tan -1 0.5 = 26.6° Tan ° = O ÷ A Tan y° = 12 ÷ 15 Tan y° = 0.8 Shift (Inv) (2ndF) Tan -1 0.8 = 38.6° 5 cm 15 cm 12cm 2.5 cm x°x° y°y°

6. O = Tan o x A Tangent Ratio To find an opposite side we need 1 side (adjacent) and the included angle. O = Tan ° x A O = Tan 45° x 9 O = 1 x 9 O = 9 cm O = Tan ° x A O = Tan 75° x 6 O = 3.732050808 x 6 O = 22.4 cm 9 cm 45° 6 cm 75° a a