Adjacent side

In the context of a right triangle, the adjacent side is the side that touches or is next to a specific angle you're examining, excluding the hypotenuse (the longest side). For example, if you're looking at an angle within the triangle, the adjacent side is the one directly connected to that angle along with the hypotenuse. It helps in calculating ratios like cosine, which compares the length of this side to the hypotenuse. Essentially, the adjacent side is the side "next to" or "beside" the angle in question, providing a reference for understanding relationships between the sides.