Geom2-5hour3
- 1. Geom25hour3.notebook September 20, 2011 BELL WORK: Find m UBF. U V (x+46)0 (4x2)0 B A F Agenda for the Day: • questions • 2.5 Addition and Subtraction Properties • exit slip • work on homework 1
- 2. Geom25hour3.notebook September 20, 2011 After today's class, you should be able to: 1. Use addition and subtraction properties of segment lengths and angle measures as reasons in proofs. 2. Use the same properties to find segment lengths and angle measures. 2.5 Addition and Subtraction Properties 7 3 7 Ex: A B C D Compare AB + BC and BC + CD Ex: Q N C J K A Compare KA + AQ and NC + CJ 2
- 3. Geom25hour3.notebook September 20, 2011 Addition Property (segments): If a segment is added to 2 congruent segments, then the sums are congruent. Addition Property REMIX (segments): If congruent segments are added to congruent segments, the sums are congruent. Compare 1 + 2 and 2 + 3 1 2 3 Addition Property (angles): If an angle is added to 2 congruent angles, then the sums are congruent. S W G N B Y V T Addition Property REMIX (angles): If congruent angles are added to congruent angles, the sums are congruent. 3
- 4. Geom25hour3.notebook September 20, 2011 Compare G H EFH GFH E J and GFJ GFH F Subtraction Properties: If a segment (or angle) is subtracted from congruent segments (or angles), then the differences are congruent. Compare RS + SB and VP + PO R V S P B O Subtraction Properties REMIX: If congruent segments (or angles) are subtracted from congruent segments (or angles), the differences are congruent. When do you use the Addition Property vs. the Subtraction Property in a proof? • Use the Addition Property when the angles or segments are bigger in the conclusion than in the given. • Use the Subtraction Property when the angles or segments are smaller in the conclusion than in the given. 4
- 5. Geom25hour3.notebook September 20, 2011 p.85 #2 M Given: Prove: G H J K p.85 #5 H G Given: Prove: E F 5
- 6. Geom25hour3.notebook September 20, 2011 EXIT SLIP: p.86 #1 HOMEWORK: p.86 #2,3,6,8 due Thursday not + or property 6