Law of Cosines

Law of Cosines

OBJECTIVES:​

A. Answer a 5 - item quiz thru - quizizz app.​

At the end of this session students will be able to:​

REVIEW:​

​Directions: Answer each questions.

Multiple Choice

1. What is the opposite side of $$\angle A$$   in the oblique triangle?

• Side a

• Side b

• Side c

• Cannot be determined

Multiple Choice

2. What is the opposite angle of "side c" in the oblique triangle?

• $$\angle A$$  

• $$\angle B$$  

• $$\angle C$$  

• Cannot be determined

Multiple Choice

3. What is the opposite side of $$\angle B$$   in the oblique triangle?

•  side a

•  side b

•  side c

• Cannot be determined

Let us have a Quiz!​

Directions: Read and answer each questions.

Multiple Choice

1. which is true about the law of cosines?

• The square of any side of a triangle is equal to the sum of the squares of the other two sides minus the product of these sides and the cosine of their included angle.

• It is used to solve problems involving oblique triangles given two sides and an excluded angle.

• It is used to solve problems involving oblique triangles given three angles.

• None of the above

Multiple Choice

2. Referring to the figure which angle can you say for certain is the largest even before solving the triangle?

• $$\angle A$$  

• $$\angle B$$  

• $$\angle C$$  

• Cannot be determined

​Since the sides and angles of the oblique triangle is proportional, if it has the largest side it also has the largest angle

Multiple Choice

3. In $$\Delta\ XYZ$$   , x = 20.4, y = 16.4, z = 23.1 find the $$\angle Z$$  

• $$74^o$$  

• $$75^o$$  

• $$76^o$$  

• $$77^o$$  

Multiple Choice

4. In $$\Delta\ ABC$$  , $$m\angle A\ =\ 36^o$$  , b = 17 cm, and c = 12 cm. Find the measure of side "a"

• 8

• 9

• 10

• 11

Multiple Choice

5. in $$\Delta\ ABC\$$  , if a = 30, b = 25, and c = 40. Find $$\angle B$$  

• $$39^o$$  

• $$38^o$$  

• $$37^o$$  

• Undefined