Solving Right TrianglesGeometry H2 (Holt 8-3) K. Santos

Identifying Parts in Right Triangle

A B

C

Using <A Using <CHypotenuse:

Opposite Side:

Adjacent Side:

Trigonometric Ratios:

SOH-CAH-TOA

Sine ϑ = = SOH

Cosine ϑ = = CAH

Tangent ϑ = = TOA

Inverse Trigonometric Functions

If = x then = m<A

If = x then = m<A

If = x then = m<A

These rules tell use that we are going to use the inverse of the functions to find the angle

On your calculator you will be using the inverse key (2nd key)

Use calculator to find angle

Use your calculator to find each angle measure to the nearest degree.

1.

Example—Finding an angle

Find x. 5

x 9

Find the unknown measures.

Find the unknown measures. Round the lengths to the nearest hundredths and angle measures to the nearest degree. 5

S R

5.7T

To find missing side use pythagorean theorem

Find the angle measurements

The side lengths of a right triangle are: 6, 8, and 10. Find the measures of the acute angles in the triangle. Round to the nearest degree. A

B C

Find the sin and cos of different angles

Percentage of grade problem

A highway sign warns that a section of road ahead has a 7% grade. To the nearest degree, what angle does the road make with a horizontal line?

x

7% = = =