1. Special Triangles: 45 o -45 o -90 o 1.1 45° x x Example: 45° 7 7 x x

2. Special Triangles: 30 o -60 o -90 o 1.1 2x2x x 60° 30° 20 10 60° 30° Example:

3. Trigonometric Ratios 1.2 SOH – CAH – TOA θ 5 12 13 Example:

4. Inverse Trigonometric Ratios1.3 SOH – CAH – TOA θ 27 35 When finding angle measures use the inverse of the trigonometric functions: Example:

5. Trig Ratios of Complementary Angles 1.4 sin A = cos B cos A = sin B tan A = Examples: 1). sin 40 o = cos 50 o 2). cos 17 o = sin 73 o 3). tan 22 o = 4). If sin A = 0.3, then cos B = 0.3 5). If tan B = ½, then tan A = 2

6. Trig Ratios of Similar Triangles 1.4 ΔDOG ~ ΔCAT sin D = sin C cos D = cos C tan D = tan C Examples: sin C = sin D = cos T = cos G = tan C = tan D = 3 4 5