Trigonometry

Applications

Review

• Trigonometry is the study of triangles and the relationships between their sides and angles.

• Important terms : Hypotenuse, Opposite, Adjacent.

• SOH-CAH-TOA• Finding sides and angles in right-angled

triangles.• Angles in degrees and minutes.• Angles of elevation and depression.

Which side is it?

Hypotenuse

Adjacent

Opp

osite

SOH-CAH-TOA

• A pnemonic to remember the 3 trigonometric ratios:

Finding sides and angles

1. Which trigonometric ratio?2. Make an equation.3. Solve the equation.

Find the…

Side marked x

38°

46 cmx

Find the…

Side marked x

29°

19 m

x

Find the…

Side marked x

32°

46 c

m

x

Find the…

Angle marked

35 cm

18 c

m

Find the…

Angle marked

29 cm

12 c

m

Degrees and Minutes

Greater accuracy in measuring angles is achieved by measuring to the nearest minute.

1° = 60’

To enter an angle into the calculator in degrees and minutes use this button:

Angle of elevation

The angle between the horizontal and line of sight when looking upwards to a point.

Angle of depression

The angle between the horizontal and line of sight when looking downwards to a point.

Trig Problem

Jed stands 80 m from the base of a tree that is 39 metres tall. What is the angle of elevation to the top of the tree to the nearest minute?

80 m

39 m

(Press the angle button)

End of Review