8.3 Ratios in Right Triangles To find trig ratios using right triangles To solve problems using trig ratios

Background trigonometry- the word comes from 2 Greek words trigon-meaning triangle metron meaning measure. hypotenuse A B C Adjacent opposite A ratio of the lengths of sides of a right triangle .

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OS AN IN pposi te djacent pposi te djacent SOH CAH TOA ypotenuse What to remember

Example Find sin A, cos A, tan A, sin B, cos B, and tan B. Express each ratio as a fraction and as a decimal B 13 5 A C 12

Example Find the value of each ratio to the nearest ten-thousandth sin 7o = .1219 cos 30o = .8660 Example Find the measure of each angle to the nearest tenth degree tan C = 9.4618 sin A = .7245 A = sin-1 .7245 C = 84o A = 46.4o

Example Find x determine the relationship between the given angle and the sides x 63o cross multiply solve for x 20 .891x = 20 x = 22.45

Homework Put this in your agenda Pg 416 17 - 37 odd, 38 - 49