On the left constructed triangle FED with right angle D. On the right, triangle ABC with AC = b, CB = a, and AB = c.

Given: ΔABC where CB=a, AC=b, and AB=c and a2+b2=c2

Construct: Right ΔDEF such that AC¯¯¯¯¯¯¯¯≅FD¯¯¯¯¯¯¯¯ and CD¯¯¯¯¯¯¯¯≅DE¯¯¯¯¯¯¯¯

Prove: ΔABC is a right triangle

Read the statements of proof. Then, answer the question.

Statements Reasons
1. ΔABC where CB=a, AC=b, and AB=c and a2+b2=c2 1. Given
2. Construct right ΔDEF such that AC¯¯¯¯¯¯¯¯≅FD¯¯¯¯¯¯¯¯ and CD¯¯¯¯¯¯¯¯≅DE¯¯¯¯¯¯¯¯ 2. Construction
3. (AB)2=(AC)2+(CB)2 3. Substitution Property
4. 4. Pythagorean Theorem
5. AC=FD

CB=DE

5. Definition of congruence
6. (EF)2=(AC)2+(CB)2 6.
7. (EF)2=(AB)2 7. Transitive Property
8. 8. Calculations (square root)
9. EF¯¯¯¯¯¯¯¯≅AB¯¯¯¯¯¯¯¯ 9. Definition of congruence
10. ΔABC≅ΔFED 10. SSS Congruence Theorem
11. ∠C≅∠D 11. CPCTC Theorem
12. m∠C=m∠D 12. Definition of congruence
13. m∠D=90° 13.
14. m∠C=90° 14.
15. ΔABC is a right triangle 15. Definition of right triangles
What reason justifies statement 6?

(1 point)
Responses

Pythagorean Converse
Pythagorean Converse

Reflexive Property
Reflexive Property

Substitution Property
Substitution Property

Pythagorean Theorem
Pythagorean Theorem

1 answer

The correct reason that justifies statement 6, which asserts that \((EF)^2 = (AC)^2 + (CB)^2\), is:

Pythagorean Theorem

This is because statement 6 applies the Pythagorean Theorem to the right triangle DEF, where the sides \(FD\) and \(DE\) correspond to sides \(AC\) and \(CB\) of triangle ABC, respectively, and \(EF\) corresponds to the hypotenuse \(AB\).