Laws of Cosine Study Notes

Laws of Cosine

• Purpose: Used for solving triangles in situations with SAS (Side-Angle-Side) or SSS (Side-Side-Side) configurations.

• Formula: The Laws of Cosine relate the lengths of sides of a triangle to the cosine of one of its angles.

Application Examples

• Example 1: Given sides a = 7, b = 12, and angle C = 59.3°.

  • Task: Solve for the missing side(s) and angle(s). Round answers to the nearest hundredth.

• Example 2: Given sides a = 7, b = 12, and c = 13.

  • Task: Solve for the missing side(s) and angle(s). Round answers to the nearest hundredth.

Key Problems

• Problem 1: Find the unknown angle in a given triangle. Round to the nearest hundredth.
• Problem 2: Calculate the distance from point A to B. Round to the nearest hundredth.