An introductory worksheet on the trigonometric ratios sine, cosine and tangent. The exercises require to evaluate these ratios for an angle in a given triangle, to identify the trigonometric ratio that corresponds to a given ratio for a given triangle, to use a calculator to evaluate the trigonometric ratio of a given angle or the angle given one of its trigonometric ratios, to associate the sine or cosine of an angle to the cosine or sine of its complementary angle and and to solve word problem