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

What is the length of side x?

• 130 cm

• 112 cm

• 150 cm

• 105 cm

To approximate the length of a marsh, a surveyor walks 425 meters from point A to point B. Then the surveyor turns 65º and walks 300 meters to point C. Approximate the length AC of the marsh.

• 250

• 615

• :)

• Not me

Which Law would you use?

• Law of Sines

• Law of Cosines

• Law of the Jungle

• Law of Gravity

Use law of Sines to find side c.

Round your answer to the nearest hundredth

Mathematical Equivalence

OFF

cos B = ? Remember: Cosine ratio is adjacent/hypotenuse

• 12/13

• 12/5

• 5/13

• 5/12

Which Law would you use?

• Law of Sines

• Law of Cosines

• Law of the Jungle

• Law of Gravity

Use law of Sines to find angle C.

Round your answer to the nearest tenth

Mathematical Equivalence

OFF

What is the correct ratio?

• 9/41

• 40/41

• 9/40

• 40/9