Plz explain and prove the triangles congruence.

(3) ∠BCA ≅ ∠DAC

Step-by-step explanation:

BC and AD are parallel.  AC is a transversal line passing through both lines.  That means ∠BCA and ∠DAC are alternate interior angles.  Therefore, they are congruent.

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11