 Convex body

A convex body in ${\mathbb{R}}^n$ is a compact convex set with nonempty interior in the ambient Euclidean space. It consequently has positive finite Lebesgue measure. A filled rectangle with positive side lengths and a closed positive-radius Euclidean disk are planar convex bodies. A line segment in ${\mathbb{R}}^2$ has empty ambient interior and is not a convex body under this convention. This is the convention used in the Brunn-Minkowski theorem. ^[ref]

A convex body is a specific type of geometric figure in Euclidean space that possesses certain characteristics. Formally, a convex body can be defined as follows: 1. **Compactness**: A convex body is a compact set, meaning it is closed and bounded.