Answer:
5. BE
7. Hypotenuse leg
Explanation:
I had constructed it. See the attachment
Statement or construction (Reason in bracket)
1. AB ║ CD
2 Construct BE perpendicular to CD such that point E is on CD.
3. Construct CF perpendicular to AB such that point F is on AB.
4. m ∡CFB = m ∡BEC =90° (All °perpendicular measures 90°(2,3))
Since all angles are 90°, we can say that BECF is rectangle or square.
5. CF = BE (Any point on one parallel line is the same distance from the other line on a perpendicular transversal (1,2,3).
6. BC = BC (They are measures of the same segment)
7. ΔBCF ≅ ΔCBE( Hypotenuse leg congruence (4,6,5))
The hypotenuse leg congruence (HL) theorem states that two right triangles are congruent if the hypotenuse and a leg of one triangle are congruent to the hypotenuse and a leg of the other triangle.
8. ∡FBC ≅ ∡ECB( Corresponding parts of congruent figures are congruent (7))