80 likes | 189 Views
Aim 3.12: To Use CPCTC to Prove Other Things. Do Now: Solve the following proof: Given: AB AD BC CD Prove: Angle B Angle D Homework: Packet Page 17 #1 & #2. A. B. D. C. Aim 3.12: To Use CPCTC to Prove Other Things. Example:. Given: AD is perpendicular to BC
E N D
Aim 3.12: To Use CPCTC to Prove Other Things Do Now: Solve the following proof: Given: AB AD BC CD Prove: Angle B Angle D Homework: Packet Page 17 #1 & #2 A B D C
Aim 3.12: To Use CPCTC to Prove Other Things Example: Given: AD is perpendicular to BC Triangle ABC is Isosceles Prove: AD bisects BC A B C D
What Do We Need? ? ? • Parallel Lines? Congruent Alternate Interior Angles • Isosceles Triangle? A Pair of Congruent Sides & Angles • Side or Angle Bisector? Two Congruent Sides or Angles that make up a larger side or angle • Midpoint? A pair of congruent sides ? ? Aim 3.12: To Use CPCTC to Prove Other Things
Aim 3.12: To Use CPCTC to Prove Other Things Example: Given: A is the midpoint of GT and IN Prove: GI NT G N A I T
Aim 3.12: To Use CPCTC to Prove Other Things Example: Given: JT is perpendicular to ES Angle E Angle S Prove: JT bisects ES J E S T
Aim 3.12: To Use CPCTC to Prove Other Things Proof: Statement Reason • JT is perpendicular to ES 1. Given • Angle ETJ & STJ are 2. Perpendicular lines right angles form right angles • Angle ETJ Angle STJ 3. All right angles are = • Angle E Angle S 4. Given • JT JT 5. Reflexive Property • ETJ STJ 6. AAS • ET ST 7. CPCTC • JT bisects ES 8. Two sides show a bisector cuts a line in ½
Aim 3.12: To Use CPCTC to Prove Other Things Example: Given: HI HE HK bisects IE Prove: HK bisects Angle IHE H I E K
Aim 3.12: To Use CPCTC to Prove Other Things Proof: Statement Reason • HI HE 1. Given • HK bisects IE 2. Given • IK KE 3. A bisector cuts a side in ½ • HK HK 4. Reflexive Property • IHK EKH 5. SSS • Angle IHK Angle EHK 6. CPCTC • HK bisects Angle IHE 7. Two angles show a bisector cuts an angle in ½