Key Concepts: Geometric Probability

Definition

Geometric probability uses lengths, areas, or volumes to calculate the likelihood of an event.

Length Model

P(event) = favorable length / total length

Area Model

P(event) = favorable area / total area

Examples

• Probability of a randomly thrown dart landing in a circle inscribed in a square: P = πr² / (2r)² = π/4 ≈ 0.785.
• Probability of landing on a segment within a number line.