Example 1: Right-Angle Triangle
Let's consider a right-angle triangle where we know the length of the adjacent side is 3 cm, and the hypotenuse is 5 cm. To find the cosine of the angle, we'd use:
cos(θ) = Adjacent / Hypotenuse = 3/5
Example 2: Sin and Cos Relationship
Did you know? For any angle θ, sin²(θ) + cos²(θ) = 1. This is the Pythagorean identity in trigonometry. Try verifying it with θ = 45°!