# Trigonometry

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Slide 1: Slide
WiskundeMiddelbare schoolvwoLeerjaar 3

This lesson contains 26 slides, with interactive quiz, text slides and 1 video.

## Items in this lesson

#### Slide 1 -Slide

6.1 & 6.2
Angle of Elevation
Tangent

#### Slide 3 -Video

In Chapter 6 - Trigonometry
When you have a right-angled triangle you can use the trigonomic ratios tangent, sine and cosine to calculate the length of a side or the size of an angle.

SOH CAH TOA

Regel
Invullen
Antwoord

Also remember:

#### Slide 7 -Slide

How to calculate the length of a side or angle in a right-angled triangle

- make a sketch
- include all known data (opposite, hypotenuse and adjacent sides)
- write down what you know and what you are trying to calculate so that you can use SOH CAH TOA to choose which ratio to use
- write down the ratio and fill in what you know

#### Slide 8 -Slide

when to use tan or shift tan?
Use  tan, sin and cos when you know the angle.

Use shift tan, shift sin and shift cos when you know the ratio of lengths of sides and you want to calculate the angle

#### Slide 9 -Slide

Sine and Cosine
VWO: ex 15 t/m 20 on pages 200 t/m 202
HAVO: ex 21 t/m26 on pages 210 t/m 212

#### Slide 11 -Slide

Calculating in right-angled triangles
VWO: ex 21 t/m 26 on pages 204 t/m 206
HAVO: ex 27 t/m 32 on pages 214 t/m 216

#### Slide 12 -Slide

How to make a right-angled triangle by drawing an auxillary line
In a triangle that has no right-angle you first have to draw an auxillary line to make a right-angled triangle. You do this by drawing a line perpendicular to a side and passing through the opposite vertex.

#### Slide 15 -Slide

How to calculate an angle between two line segments in a solid
Look for a cross-section in which both line segments lie
Make a sketch of this cross-section and include all known date.
Check if you can calculate the angle. Sometimes you have to calculate the length of a line segment first.
Calculate the angle. Do not round the intermediate answers.

#### Slide 17 -Slide

Which ratio do you use to calculate the angle of elevation?

#### Slide 18 -Open question

Practise exercises
Mixed Exercises
Test Yourself
Extra exercises

#### Slide 25 -Slide

Do you have any questions?