. Definition 27: let u be an internal vertex If there is a directed edge(u, w) from u to w. then w is called child of u. and u is called the parent of w. If the vertices W and w2 are child of u, then w, and w2 are called brothers. If there a directed path from u to z then z is called descendant of u and u is called ancestors of w. The level of a vertex v is the length of the unique path from the root to this vertex. The level of the root is defined to be zero. The height of a rooted tree is the maximum of the levels of all vertices .o Note: The parent of w is unique❖ Definition 27: Let u be an internal vertex. If there is a directed edge (u,w) from u to w, then w is called child of u, and u is called the parent of w. If the vertices w1 and w2 are child of u, then w1 and w2 are called brothers. If there a directed path from u to z, then z is called descendant of u. and u is called ancestors of w. The level of a vertex v is the length of the unique path from the root to this vertex. The level of the root is defined to be zero. The height of a rooted tree is the maximum of the levels of all vertices. ❖ Note: The parent of w is unique