**2.** Every leaf has the same depth equal to the height of the tree.

**3.** The number of keys is bounded in terms of the minimum degree
t 2.

n(x) t-1 (except root 1)

#children(x) t (except root 0), leaves = 0

n(x) 2t - 1

#children 2t (except leaves which = 0)

If n(x) = 2t - 1 then n is a full node.

For example, if t = 3:

- Root: n(x) = [1..5], #children = [0..6]
- Internal node: n(x) = [2..5], #children = [3..6]
- Leaf: n(x) = [2..5], #children =