Presentation is loading. Please wait.

Presentation is loading. Please wait.

Law of Cosines Chapter 5, Section 6.

Published byDiana Norton Modified over 5 years ago

Similar presentations

Presentation on theme: "Law of Cosines Chapter 5, Section 6."— Presentation transcript:

1 Law of Cosines Chapter 5, Section 6

2 What is the law of cosines?
Used to provide a relationship between the angles and sides of a triangle Relates to the pythagorean theorem First appeared in 1895 in a book by George Albert Wentworth

3 Law of Cosines Triangle

4 Examples – 3 sides

5 Examples – 2 sides, 1 angle

6 Area of a Triangle These are 3 equivalent representations
Only need to use one to find the area

7 Examples – find the area

8 Homework page 494 #3-18 multiples of 3
Exit Slip: Explain how you know to use the law of sines or the law of cosines in a problem.

Download ppt "Law of Cosines Chapter 5, Section 6."

Similar presentations

Geometry Chapter 8.  We are familiar with the Pythagorean Theorem:

Geometry Chapter 8.  We are familiar with the Pythagorean Theorem:
Math 112 Elementary Functions Section 2 The Law of Cosines Chapter 7 – Applications of Trigonometry.

Math 112 Elementary Functions Section 2 The Law of Cosines Chapter 7 – Applications of Trigonometry.
Starter a 6 c A 49° 96° 1.Use the Law of Sines to calculate side c of the triangle. 2.Now find the Area of a Triangle.

Starter a 6 c A 49° 96° 1.Use the Law of Sines to calculate side c of the triangle. 2.Now find the Area of a Triangle.
The Pythagorean Theorem. The Right Triangle A right triangle is a triangle that contains one right angle. A right angle is 90 o Right Angle.

The Pythagorean Theorem. The Right Triangle A right triangle is a triangle that contains one right angle. A right angle is 90 o Right Angle.
Law of Cosines. We use the law of cosines and the law of sines because we need to be able to find missing sides and angles of triangles when they are.

Law of Cosines. We use the law of cosines and the law of sines because we need to be able to find missing sides and angles of triangles when they are.
03.16.10 Do Now Find the missing angle measures. 60° 45°

Do Now Find the missing angle measures. 60° 45°
Section 3-5 p. 137 Goal – to solve problems using the Pythagorean Theorem.

Section 3-5 p. 137 Goal – to solve problems using the Pythagorean Theorem.
Right Triangles and Trigonometry Chapter 8. Pythagorean Theorem a 2 + b 2 = c 2 right triangle a 2 + b 2 < c 2 obtuse triangle a 2 + b 2 > c 2 acute triangle.

Right Triangles and Trigonometry Chapter 8. Pythagorean Theorem a 2 + b 2 = c 2 right triangle a 2 + b 2 < c 2 obtuse triangle a 2 + b 2 > c 2 acute triangle.
5.8 The Law of Cosines Law of Cosines – Law of Cosines allows us to solve a triangle when the Law of Sines cannot be used. Most problems can be solved.

5.8 The Law of Cosines Law of Cosines – Law of Cosines allows us to solve a triangle when the Law of Sines cannot be used. Most problems can be solved.
Triangle Warm-up Can the following side lengths be the side lengths of a triangle?

Triangle Warm-up Can the following side lengths be the side lengths of a triangle?
11/11/2015 Geometry Section 9.6 Solving Right Triangles.

11/11/2015 Geometry Section 9.6 Solving Right Triangles.
CHAPTER 8 Right Triangle Trigonometry. 5 Videos to Watch 1)http://www.khanacademy.org/math/geometry/right_triangles_topic/pyth_theor/v/the- pythagorean-theoremhttp://www.khanacademy.org/math/geometry/right_triangles_topic/pyth_theor/v/the-

CHAPTER 8 Right Triangle Trigonometry. 5 Videos to Watch 1) pythagorean-theoremhttp://
6.1 Laws of Sines. The Laws of Sine can be used with Oblique triangle Oblique triangle is a triangle that contains no right angle.

6.1 Laws of Sines. The Laws of Sine can be used with Oblique triangle Oblique triangle is a triangle that contains no right angle.
Homework Questions. LOGS Warm-up Convert from log form to exponential form Convert from exponential form to log form Expand Condense.

Homework Questions. LOGS Warm-up Convert from log form to exponential form Convert from exponential form to log form Expand Condense.
Chapter 8 Section 8.2 Law of Cosines. In any triangle (not necessarily a right triangle) the square of the length of one side of the triangle is equal.

Chapter 8 Section 8.2 Law of Cosines. In any triangle (not necessarily a right triangle) the square of the length of one side of the triangle is equal.
TRIGONOMETRY Lesson 2: Solving Right Triangles. Todays Objectives Students will be able to develop and apply the primary trigonometric ratios (sine, cosine,

TRIGONOMETRY Lesson 2: Solving Right Triangles. Todays Objectives Students will be able to develop and apply the primary trigonometric ratios (sine, cosine,
1 What you will learn  How to solve triangles by using the Law of Cosines  How to find the area of triangles if the measures of the three sides are given.

1 What you will learn  How to solve triangles by using the Law of Cosines  How to find the area of triangles if the measures of the three sides are given.
Section 9.2-9.3. Take a note: Up until now, our work with triangles has involved right triangles, And for that we use the Pythagorean Theorem. But there.

Section Take a note: Up until now, our work with triangles has involved right triangles, And for that we use the Pythagorean Theorem. But there.
4.7 – Square Roots and The Pythagorean Theorem Day 2.

4.7 – Square Roots and The Pythagorean Theorem Day 2.
Section 1.3.2 Law of Cosines. Law of Cosines: SSS or SAS Triangles 1-106 Use the diagram to complete the following problems, given triangle ABC is acute.

Section Law of Cosines. Law of Cosines: SSS or SAS Triangles Use the diagram to complete the following problems, given triangle ABC is acute.

Similar presentations

Ads by Google