4.3 Proving Δs are : SSS and SAS pg. 212
Remember? As of yesterday, Δs could only be if ALL sides AND angles were NNOT ANY MORE!!!! TThere are two short cuts to add.
Post. 19 Side-Side-Side (SSS) post If 3 sides of one Δ are to 3 sides of another Δ, then the Δs are .
Meaning: If seg AB seg ED, seg AC seg EF & seg BC seg DF, then ΔABC ΔEDF. ___ A BC E DF
Given: seg QR seg UT, RS TS, QS=10, US=10 Prove: ΔQRS ΔUTS Q R S T U 10
Proof Statements Reasons given 2. QS=US 2. subst. prop. = 3. Seg QS seg US 3. Def of segs. 4. Δ QRS Δ UTS 4. SSS post
Post. 20 Side-Angle-Side post. (SAS) If 2 sides and the included of one Δ are to 2 sides and the included of another Δ, then the 2 Δs are .
If seg BC seg YX, seg AC seg ZX, and C X, then ΔABC ΔZXY. B A C X Y Z ) (
Given: seg WX seg. XY, seg VX seg ZX, Prove: Δ VXW Δ ZXY 12 W V X Z Y
Proof Statements Reasons 1. seg WX seg. XY 1. given seg. VX seg ZX 2. 1 2 2. vert s thm 3. Δ VXW Δ ZXY 3. SAS post
Given: seg RS seg RQ and seg ST seg QT Prove: Δ QRT Δ SRT. Q R S T
Proof Statements Reasons 1. Seg RS seg RQ1. Given seg ST seg QT 2. Seg RT seg RT2. Reflex prop 3. Δ QRT Δ SRT3. SSS post
Given: seg DR seg AG and seg AR seg GR Prove: Δ DRA Δ DRG. D A R G
Proof Statements 1.seg DR seg AG Seg AR seg GR 2. seg DR Seg DR 3. DRG & DRA are rt. s 4. DRG DRA 5. Δ DRG Δ DRA Reasons 1.Given 2.reflex. Prop of 3. lines form 4 rt. s 4. Rt. s thm 5. SAS post.
Assignment