Law of Sines & Cosines

Identify the Law of Sines

• Sin²x + Cos²x =1

• Sin(A)/a = Sin(B)/b = Sin(C)/c

• Sin(A)Sin(B)Sin(C) = 1

• Soh-Cah-Toa

Use the Law of Cosines to find the value of x.  (Level 1)

• 41.7

• 51.7

• 61.7

• 71.7

Find the length of Side BC.

• 33

• 24

• 12

• 29

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

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, and from Jamie to the bird is 63.  How far away is the bird from Amanda?

• 25.23

• 23.19

• 22.15

• 20.85

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 is the bird from Amanda?

• 25.23

• 23.19

• 22.15

• 20.85

What is the measure of angle A?

• 50 degrees

• 60 degrees

• 78 degrees

• 74 degrees

How Many Triangles would be possible?

• 2

• 1

• 0

• INFINITE

What is the length of side x?

• 6.57 cm

• 7 cm

• 7.44 cm

• 26.33 cm

Find: a

β = 70°

c = 11

α = 40°

• 11

• 7.5

• 70

• 8