Pascal's triangle displays binomial coefficients in triangular pattern. Row n contains C(n,0), C(n,1), ..., C(n,n). Rows: Row 0: 1; Row 1: 1 1; Row 2: 1 2 1; Row 3: 1 3 3 1; Row 4: 1 4 6 4 1. Each entry = sum of two entries above (C(n,r) = C(n-1,r-1) + C(n-1,r)). Binomial theorem: (a+b)^n = Σ C(n,k) a^(n-k) b^k. Coefficients from row n of Pascal's triangle. Example: (a+b)³ = a³ + 3a²b + 3ab² + b³ (coefficients 1,3,3,1 from row 3). Applications: Expanding binomials, finding specific terms, combinatorial identities. Exam tip: Memorize up to row 5 for quick reference. Understand relationship between Pascal's triangle and combinations.