Geometry Notes

Lesson 5.3B TrigonometryT.2.G.6 Use trigonometric ratios (sine, cosine, tangent) to determine lengths of sides and measures of angles in right triangles including angles of elevation and angles of depressionT.2.G.7 Use similarity of right triangles to express the sine, cosine, and tangent of an angle in a right triangle as a ratio of given lengths of sides

Solving for unknown valuesSteps:1.

2.

3.

4.

Label the sides as: opposite, adjacent, hypotenuse.

Decide which trig ratio is needed:

(sine, cosine, or tangent).

Set up Equation

Use Calculator to Solve.

Example #1 :Find x. Round your answer to the

nearest tenth.

5750

x

Example #2Find x. Round your answer to the

nearest tenth.

1851

x

Example #3Find x. Round your answer to the

nearest tenth.

x46

3

Example #4Find x. Round your answer to the

nearest tenth.

x

3118

Now You Try…Find x. Round your answer to the

nearest tenth.

x

46

3

Now You Try…Find x. Round your answer to the

nearest tenth.

x

31

18