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  • Pedro is going to use SAS to prove that △PQR ≅ △SQR. Which of these is a necessary step in Pedro’s proof? O A. Prove that ∠QPR ≅ ∠QSR by the Isosceles Triangle Theorem. O B. Prove that QR ≅ QR by the reflexive property. O C. Prove that PQ ≅ SQ by CPCTC. O D. Prove that ∠PQR ≅ ∠SQR by vertical angles.

Pedro is going to use SAS to prove that △PQR ≅ △SQR. Which of these is a necessary step in Pedro’s proof? O A. Prove that ∠QPR ≅ ∠QSR by the Isosceles Triangle Theorem. O B. Prove that QR ≅ QR by the reflexive property. O C. Prove that PQ ≅ SQ by CPCTC. O D. Prove that ∠PQR ≅ ∠SQR by vertical angles.

Pedro is going to use SAS to prove that △PQR ≅ △SQR. Which of these is a necessary step in Pedro's proof? O A. Prove that ∠QPR ≅ ∠QSR by the Isosceles Triangle Theorem. O B. Prove that QR ≅ QR by the reflexive property. O C. Prove that PQ ≅ SQ by CPCTC. O D. Prove that ∠PQR ≅ ∠SQR by vertical angles.

Answer

Answer: B. Prove that \( \overline{QR} \cong \overline{QR} \) by the reflexive property.

Explanation: To use the Side-Angle-Side (SAS) congruence theorem, we need to show that two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle. The reflexive property is used to show that the side \( \overline{QR} \) is congruent to itself, which is a necessary step in proving the triangles congruent by SAS.

Steps:

  1. Identify the triangles: We are considering triangles \( \triangle PQR \) and \( \triangle SQR \).
  1. Apply the SAS theorem: For SAS, we need:
  • Two pairs of congruent sides
  • The included angle between those sides to be congruent
  1. Congruent sides:
  • \( \overline{QR} \cong \overline{QR} \) by the reflexive property (same line segment in both triangles).
  • \( \overline{PR} \cong \overline{RS} \) because \( R \) is the midpoint of \( \overline{PS} \).
  1. Included angle:
  • \( \angle PRQ \cong \angle SRQ \) because they are both right angles (given).
  1. Conclusion: With two sides and the included angle congruent, \( \triangle PQR \cong \triangle SQR \) by SAS.

Thus, proving \( \overline{QR} \cong \overline{QR} \) by the reflexive property is a necessary step in Pedro’s proof.

Related

(2) O3 + H → O2 + OH k2 = 1.78×10^-11 cm^3 s^-1 (3) O + OH → O2 + H k3 = 4.40×10^-11 cm^3 s^-1 (5) O + HO2 → O2 + OH k5 = 3.50×10^-11 cm^3 s^-1 (6) H + HO2 → O2 + H2 k6 = 5.40×10^-12 cm^3 s^-1 (9) OH + HO2 → O2 + H2O2 k9 = 4.00×10^-11 cm^3 s^-1 (10) HO2 + HO2 → O2 + H2O2 k10 = 2.50×10^-12 cm s^-1 (11) O + O2 + M → O3 + M k11 = 1.05×10^-34 cm^6 s^-1 (14) H + O2 + M → HO2 + M k14 = 8.08×10^-32 cm^6 s^-1 (15) H + H + M → H2O + M k15 = 3.31×10^-27 cm^6 s^-1 (16) O2 + hv → 2 O k16 = (1.26×10^-8 s^-1) φ (17) H2O + hv → H + OH k17 = (3.4×10^-6 s^-1) φ (18) O3 + hv → O2 + O k18 = (7.10×10^-5 s^-1) φ

Table 1 Reactions, rate constants and activation energies used in the model* No. Reaction kopt (M⁻¹ s⁻¹) 1 OH + H₂ → H + H₂O 3.74 x 10⁷ 2 OH + HO₂ → HO₂ + OH⁻ 5 x 10⁹ 3 OH + H₂O₂ → HO₂ + H₂O 3.8 x 10⁷ 4 OH + O₂ → O₂ + OH 9.96 x 10⁹ 5 OH + HO₂ → O₂ + H₂O 7.1 x 10⁹ 6 OH + OH → H₂O₂ 5.3 x 10⁹ 7 OH + e⁻aq → OH⁻ 3 x 10¹⁰ 8 H + O₂ → HO₂ 2.0 x 10¹⁰ 9 H + HO₂ → H₂O₂ 2.0 x 10¹⁰ 10 H + H₂O₂ → OH + H₂O 3.44 x 10⁷ 11 H + OH → H₂O 1.4 x 10¹⁰ 12 H + H → H₂ 1.94 x 10¹⁰ 13 e⁻aq + O₂ → O₂⁻ 1.9 x 10¹⁰ 14 e⁻aq + O₂ → HO₂⁻ + OH⁻ 1.3 x 10¹⁰ 15 e⁻aq + HO₂ 2.0 x 10¹⁰ 16 e⁻aq + H₂O₂ 1.1 x 10¹⁰ 17 e⁻aq + HO₂ → OH + OH⁻ 1.3 x 10¹⁰ 18 e⁻aq + H⁺ → H 2.3 x 10¹⁰ 19 e⁻aq + e⁻aq → H₂ + OH⁻ + OH⁻ 2.5 x 10⁹ 20 HO₂ + O₂ → O₂ + HO₂ 1.3 x 10⁹ 21 HO₂ + HO₂ → O₂ + H₂O₂ 8.3 x 10⁵ 22 HO₂ + HO₂ → O₂ + OH + H₂O 3.7 23 HO₂ + HO₂ → O₂ + O₂ + OH + H₂O 7 x 10⁵ s⁻¹ 24 H⁺ + O₂⁻ → HO₂ 4.5 x 10¹⁰ 25 H⁺ + O₂⁻ → O₂ 2.0 x 10¹⁰ 26 H⁺ + OH⁻ 1.4 x 10¹¹ 27 H⁺ + HO₂⁻ 2 x 10¹⁰ 28 H₂O₂ → HO₂ + H⁺ + OH⁻ 2.5 x 10⁻⁵ s⁻¹ 29 H₂O₂ → H⁺ + OH⁻ 1.4 x 10⁻⁷ s⁻¹ 30 O₂ + O₂ → O₂ + HO₂ + OH⁻ 0.3 31 O₂ + H₂O₂ → O₂ + OH + OH 16 32

(2) O3 + H → O2 + OH k2 = 1.78×10^-11 cm^3 s^-1 (3) O + OH → O2 + H k3 = 4.40×10^-11 cm^3 s^-1 (5) O + HO2 → O2 + OH k5 = 3.50×10^-11 cm^3 s^-1 (6) H2O + O → 2 OH k6 = 5.40×10^-12 cm^3 s^-1 (9) OH + HO2 → O2 + H2O k9 = 4.00×10^-11 cm^3 s^-1 (10) HO2 + HO2 → O2 + H2O2 k10 = 2.50×10^-12 cm s^-1 (11) O + O2 + M → O3 + M k11 = 1.05×10^-34 cm^6 s^-1 (14) H + O2 + M → HO2 + M k14 = 8.08×10^-32 cm^6 s^-1 (15) OH + H + M → H2O + M k15 = 3.31×10^-27 cm^6 s^-1 (16) O2 + hv → 2 O k16 = (1.26×10^-8 s^-1) φ (17) H2O + hv → H + OH k17 = (3.4×10^-6 s^-1) φ (18) O3 + hv → O2 + O k18 = (7.10×10^-8 s^-1) φ

Table 1 Reactions, rate constants and activation energies used in the model* No. Reaction kopt (M−1 s−1) 1 OH + H2 → H + H2O 3.74 x 107 2 OH + HO2 → HO2 + OH− 5 x 109 3 OH + H2O2 → HO2 + H2O 3.8 x 107 4 OH + O2 → O2− + OH 9.96 x 109 5 OH + HO2 → O2 + H2O 7.1 x 109 6 OH + OH → H2O2 5.3 x 109 7 OH + eaq− → OH− 3 x 1010 8 OH + O2− → HO2 2.0 x 1010 9 H + O2 → HO2 2.0 x 1010 10 H + HO2 → H2O2 2.0 x 1010 11 H + H2O2 → OH + H2O 3.4 x 107 12 H + OH → H2O 1.4 x 1010 13 H + H → H2 7.9 x 109 14 eaq− + O2 → O2− 1.94 x 1010 15 eaq− + O2− → HO2− + OH− 1.3 x 1010 16 eaq− + HO2 → OH− + OH 2.5 x 1010 17 eaq− + H2O2 → OH + OH− 1.3 x 1010 18 eaq− + H → H− 2.5 x 1010 19 eaq− + eaq− + H2 + OH− 3.5 x 109 20 eaq− + H2O2 + OH− 4.5 x 109 21 HO2 + O2 → O2 + HO2 3.7 22 HO2 + HO2 → O2 + H2O2 3.7 23 HO2 + HO2 → O2 + OH + H2O 7 x 105 s−1 24 HO2− + O2 4.5 x 1010 25 H2O2 → 2OH 0.035 s−1 26 H+ + O2− → HO2 2 x 1010 27 H+ + HO2− → HO2 2 x 1010 28 H2O2 → H+ + HO2− 2.5 x 10−5 s−1 29 H2O2 → H+ + HO2− 2.5 x 10−5 s−1 30 O2− + O2 → HO2 + OH− 0.3 31 O2− + H2O2 → O2 + OH− + OH 16 32 1.8 x 107

(2) O3 + H → O2 + OH k2 = 1.78×10^-11 cm^3 s^-1 (3) O + OH → O2 + H k3 = 4.40×10^-11 cm^3 s^-1 (5) O + HO2 → O2 + OH k5 = 3.50×10^-11 cm^3 s^-1 (6) H2O → O + H2 k6 = 5.40×10^-12 cm^3 s^-1 (9) OH + HO2 → O2 + H2O k9 = 4.00×10^-11 cm^3 s^-1 (10) HO2 + HO2 → O2 + H2O2 k10 = 2.50×10^-12 cm s^-1 (11) O + O2 + M → O3 + M k11 = 1.05×10^-34 cm^6 s^-1 (14) H + O2 + M → HO2 + M k14 = 8.08×10^-32 cm^6 s^-1 (15) OH + H + M → H2O + M k15 = 3.31×10^-27 cm^6 s^-1 (16) O2 + hv → 2 O k16 = (1.26×10^-8 s^-1) φ (17) H2O + hv → H + OH k17 = (3.4×10^-6 s^-1) φ (18) O3 + hv → O2 + O k18 = (7.10×10^-8 s^-1) φ