Law of Cosines Introduction

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

Find angle Z

• 20.15°

• 71.23°

• 51.06°

• 57.71°

Use Law of Cosines to find angle T

• 62.2°

• 53.1°

• 59.5°

• 64.7°

If three sides of a triangle are given, the Law of ____ is used to solve the triangle.

• Cosines
• Sines
• Tangent
• Cosecents

Which Law would you use?

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

Find m<C

• A
• B
• C
• D

Find XZ

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

Find QR

• 34.7 km
• 2.2 km
• 13.74
• 31.1 km