Meaningful Distributed Practice Planning Grade Level / Class Big Idea(s) 9-12 Geometry Preview Review Vertex Edge Graphs (Paths and Circuits) MDP1 MDP 2 MDP3 Given the vertices {A, B, C, D, E} and edges {AB, BD, DC, DC, DC, ED, BE, AD} draw the graph. List the vertices and edges in this graph. Find a path from vertex A to vertex B. Find a circuit. Find a path that visits each vertex exactly once, starting and ending at a different vertex. Probing Questions: What is a path? What is a circuit? Are there any more paths (or circuit)? Are there 8 vertices or 6 vertices in this figure? Explain. Where in the “real world” do edges cross without creating a vertex? Probing Questions: Is there only one way to draw this graph? Are there any “parallel” edges in this graph? Anticipated Student Responses: Vertices = {A, B, C, D, E, F} Edges = {AC, AD, AB, BD, CE, CF, DE} Paths & Circuits = (Multiple Answers) What is a path? What is a circuit? Some of the “vertices” are not labeled (i.e. intersections). Edge ABD (as arc ABD) Anticipated Student Responses: One possible solution: 7031 a Vertex Edge Graphs How many edges are there from D to C? Find a circuit that visits each vertex exactly once, starting and ending at the same vertex. Probing Questions: Are your solutions unique? Is there a path that visits each vertex exactly once, starting and ending at a different vertex that includes F? Is there a circuit that visits each vertex exactly once, starting and ending at the same vertex that includes F? How does removing F change this problem? Anticipated Student Responses: Hamiltonian Path = {FCEDBA} Hamiltonian Circuits = { } Hamiltonian Paths = {ABDEC, BDECA, DECAB, ECABD, CABDE} Hamiltonian Circuits = {ABDECA, BDECAB, DECABD, ECABDE, CABDEC} 1/2 7031 a Vertex Edge Graphs 2/2