Introduction to Trigonometry and 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

What is the measure of angle A?

• 50 degrees
• 60 degrees
• 78 degrees
• 74 degrees

What is the length of side x?

• 130 cm
• 112 cm
• 150 cm
• 105 cm

Use Law of Cosines to find XZ

• 16.004 meters
• 544.165 meters
• 34.7 meters
• 1204.165 meters

Find the length of Side BC.

• 33

• 24

• 12

• 29

Find the length of side AB.

• 10

• 8

• 6.1

• 4.9

What is the measure of angle A?

• 58 degrees
• 61 degrees
• 78 degrees
• 74 degrees

Find the length of side AC.

• 12

• 10

• 23

• 14