The Law of Sines, The Law of Cosines, Area of A Triangle

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)

Amanda and Jamie are standing 25 feet apart and spot a bird in the sky between them. The angle of elevation from Amanda to the bird is 55 degrees, and from Jamie to the bird is 63 degrees. How far away, to 2 decimal places, is the bird from Amanda?

• 25.23 ft

• 23.19 ft

• 22.15 ft

• 20.85 ft

Clint is building a wooden swing set for his children. Each supporting end of the swing set is to be an A-frame constructed with two 10 foot long 4-by-4s joined at a 45 degree angle. To prevent the swing set form tipping over, Clint wants to secure the base of each A-frame to concrete footings. How far apart, to three decimal places, should the footings for each A-frame be?

• 5.461 feet

• 9.743 feet

• 58.579 feet

• 7.654 feet

What is the area of this triangle to three decimal places?

• 14.494 meters squared

• 108.184 meters squared

• 54.092 meters squared

• 54.350 meters squared

What are the possible criteria for the Law of Cosines?

• SSA, SSS

• SSA, ASA

• SSS, SAS

• AAS, ASA

Find m<B to the nearest whole number.

• A

• B

• C

• D

Which Law would you use?

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