Given that in isosceles △ABC , base BC¯¯¯¯¯, BE¯¯¯¯¯⊥AC¯¯¯¯¯, and CF¯¯¯¯¯⊥AB¯¯¯¯¯, which of the following proves that BE¯¯¯¯¯≅CF¯¯¯¯¯?

1. Isosc. △ABC, base BC¯¯¯¯¯ (Given)
2. AB¯¯¯¯¯≅BC¯¯¯¯¯ (Def. of Isosc. △)
3. BE¯¯¯¯¯⊥AC¯¯¯¯¯, CF¯¯¯¯¯⊥AB¯¯¯¯¯ (Given)
4. ∠BEA and ∠CFA are Supplementary Angles (Def. of ⊥)
5. AB¯¯¯¯¯≅BC¯¯¯¯¯ (Supp. ∠s ≅ Thm.)
6. ∠A≅∠A (Reflex. Prop. of≅)
7. △ABE≅△ACF (SAS Steps 1, 6, 5)
8. BE¯¯¯¯¯≅CF¯¯¯¯¯ (CPCTC)

1. Isosc. △ABC, base BC¯¯¯¯¯ (Given)
2. AB¯¯¯¯¯≅BC¯¯¯¯¯ (Def. of Isosc. △)
3. BE¯¯¯¯¯⊥AC¯¯¯¯¯, CF¯¯¯¯¯⊥AB¯¯¯¯¯ (Given)
4. ∠BEC and ∠CFB are Supplementary Angles (Def. of ⊥)
5. AC¯¯¯¯¯≅BC¯¯¯¯¯ (Supp. ∠s ≅ Thm.)
6. ∠A≅∠B (Sym. Prop. of≅)
7. △ABE≅△ACF (SAS Steps 1, 6, 5)
8. BE¯¯¯¯¯≅CF¯¯¯¯¯ (CPCTC)

1. Isosc. △ABC, base BC¯¯¯¯¯ (Given)
2. AB¯¯¯¯¯≅AC¯¯¯¯¯ (Def. of Isosc. △)
3. BE¯¯¯¯¯⊥AC¯¯¯¯¯, CF¯¯¯¯¯⊥AB¯¯¯¯¯ (Given)
4. m∠BEA=m∠CFA=90∘ (Def. of ⊥)
5. ∠BEA≅∠CFA (Rt. ∠s ≅ Thm.)
6. ∠A≅∠A (Reflex. Prop. of≅)
7. △ABE≅△ACF (AAS Steps 5, 6, 1)
8. BE¯¯¯¯¯≅CF¯¯¯¯¯ (CPCTC)

1. Isosc. △ABC, base BC¯¯¯¯¯ (Given)
2. AB¯¯¯¯¯≅AC¯¯¯¯¯ (Def. of Isosc. △)
3. BE¯¯¯¯¯⊥AC¯¯¯¯¯, CF¯¯¯¯¯⊥AB¯¯¯¯¯ (Given)
4. m∠BEC=m∠CFB=90∘ (Def. of ⊥)
5. ∠BEC≅∠CFB (Rt. ∠s ≅ Thm.)
6. ∠A≅∠B (Sym. Prop. of≅)
7. △ABE≅△ACF (AAS Steps 5, 6, 1)
8. BE¯¯¯¯¯≅CF¯¯¯¯¯ (CPCTC)

An isosceles triangles has two sides that are congruent and a base.
AAS Congruence Theorem proves that two triangles are congruent if they possess two pairs of congruent sides and a pair of non-included congruent sides.
All corresponding parts of two congruent triangles are equal in measure to each other, based on the CPCTC Theorem.

The isosceles triangle ABC given is shown in the image attached below.

To prove that, BE ≅ CF, establish the fact that △ABE ≅ △ACF by the AAS Congruence Theorem.

Since △ABE ≅ △ACF, therefore BE ≅ CF by the CPCTC Theorem.

Thus, the correct proof that proves that BE ≅ CF is the proof in option C. (see attachment).

Learn more about AAS Congruence Theorem on:

https://brainly.com/question/3168048