Lesson 4  Solving Problems Using Right Triangles.notebook

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June 09, 2017

Learning Goal: By the end of this lesson I will be able to use SOH CAH TOA to solve word problems.

Lesson #4  Solving Problems Using Right Triangles

Solving Problems using Trig and Right TrianglesSteps:

0) Draw a diagram, using a right triangle. Label the known information.

1) Use Pythagoras, if possible - Do you have two sides and wanta third side?

2) Identify the angle that determines where O, A and H go.

3) Using SOH CAH TOA, choose the trig ratio that will solve the problem.

4) Set up the trig ratio - you will find either an angle or a side.

5) Does the answer make sense? Make a final concluding statement.

Lesson 4  Solving Problems Using Right Triangles.notebook

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June 09, 2017

Angles of Depression and Elevation

Angle of Depression: starts at a horizontal line and angles down from this line.

Angle of Elevation: starts at a horizontal line and angles up from this line.

θ

θ

Examples

1) To begin painting his tree fort, Mr. Perkins places a ladder that is 10 m long, 1.7 m from the base of the tree. For safety, ladders are supposed to be between 70o and 80o. Is the ladder that Mr. Perkins placed, safe for him to use? Draw a diagram and show a solution!

Lesson 4  Solving Problems Using Right Triangles.notebook

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June 09, 2017

2) An extension ladder reaches a maximum length of 18 m. A building has stories that are 4m high. A fire breaks out on the 4th floor; will the extension ladder reach and be safe?

A ladder is leaning against a building and makes an angle of 55° with level ground.  If the distance from the foot of the ladder to the building is 4 feet, find, to the nearest foot, how far up the building the ladder will reach.

Lesson 4  Solving Problems Using Right Triangles.notebook

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June 09, 2017

The Dodgers Communication Company must run a telephone line between two poles at opposite ends of a lake as shown below.  The length and width of the lake is 75 feet and 30 feet respectively. What is the distance between the two poles, to the nearest foot?

A ship on the ocean surface detects a sunken ship on the ocean floor at an angle of depression of 50° .  The distance between the ship on the surface and the sunken ship on the ocean floor is 200 metres.  If the ocean floor is level in this area, how far above the ocean floor, to the nearest metre, is the ship on the surface?

Attachments

Pythagorean Theorem.ggb

geogebra_thumbnail.png

geogebra.xml

SMART Notebook

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