How do I use inverse sine cosine and

• How do I use inverse sine, cosine, and tangent functions to find the angles of a triangle?

5. 4 Solve Right Triangles Inverse Trigonometric Ratios Let be an acute angle.

5. 4 Solve Right Triangles Example 1 Use an inverse tangent to find an angle measure Use a calculator to approximate the measure of to the nearest tenth of a degree. Because tan A = _____, Using a calculator, So, the measure of is approximately _______.

5. 4 Solve Right Triangles Checkpoint. Complete the following exercises. 1. In Example 1, use a calculator and an inverse tangent to approximate to the nearest tenth of a degree.

5. 4 Solve Right Triangles Example 2 Use an inverse sine and an inverse cosine Let and be acute angles in two right triangles. Use a calculator to approximate the measure of and to the nearest tenth of a degree. a. sin A = 0. 76 Solution b. cos B = 0. 17

5. 4 Solve Right Triangles Example 3 Solve a right triangle Solve the right triangle. Round your answer to the nearest tenth. Solution Step 1 Find by using the Triangle Sum Theorem.

5. 4 Solve Right Triangles Example 3 Solve a right triangle Solve the right triangle. Round your answer to the nearest tenth. Solution Step 2 Approximate BC using a ______ sine ratio. Write ratio for _____. Multiply each side by ___. Approximate ____. Simplify and round answer.

5. 4 Solve Right Triangles Example 3 Solve a right triangle Solve the right triangle. Round your answer to the nearest tenth. Solution Step 3 Approximate AC using a ______ cosine ratio. Write ratio for _____. Multiply each side by ___. Approximate ____. Simplify and round answer.

5. 4 Solve Right Triangles Example 3 Solve a right triangle Solve the right triangle. Round your answer to the nearest tenth. Solution The angle measures are _____, and _____. The side lengths are _____ feet, about _______ feet, and about ______ feet.

5. 4 Solve Right Triangles Checkpoint. Complete the following exercises. 2. Find to the nearest tenth of a degree if cos T = 0. 64. 3. Find D = 0. 48. to the nearest tenth of a degree if sin

5. 4 Solve Right Triangles Checkpoint. Complete the following exercises. 4. Solve a right triangle that has a 50 o angle and a 15 inch hypotenuse.

5. 4 Solve Right Triangles Pg. 187, 5. 4 #1 -30