Law of Sines and Cosines

Which of the following formulas shows the Law of Cosines?

• c² = a² + b² - 4ac + cosA

• c² = a² - b² - 2abcosC

• c² = a² + b² - 2abcosC

• (cos A)/a = (cos B)/b

Which Law would you use?

• Law of Sines
• Law of Cosines
• Law of the Jungle
• Law of Gravity

Which Law would you use?

• Law of Sines
• Law of Cosines
• Law of the Jungle
• Law of Gravity

Identify the Law of Sines

• Sin²x + Cos²x =1

• Sin(A)/a = Sin(B)/b = Sin(C)/c

• Sin(A)Sin(B)Sin(C) = 1

• y=Sin(x)

Find m<B to the nearest whole number.

• A

• B

• C

• D

Find angle Z

• 18.77°

• 71.23°

• 51.06°

• 57.71°

Which Law would you use?

• Law of Sines
• Law of Cosines
• Law of the Jungle
• Law of Gravity

Find the missing side.

• 15.9 in.

• 22.8 in.

• 6.54 in.

• 521.1 in.

How do you feel about The Law of Cosines?

• I understand it

• I am getting it, but need more practice

• I have no idea what is going on

Find the length of side AB. m<C = 53 degrees. m<B = 44 degrees. AC = 7.

• 8.0

• 8.8

• 9.2

• 10.3