Ineed with 21 a and b and i need to show my work

Prove that quadrilateral is a rhombus.

Which must be true in order for the relationship △zyv ~ △xwv to be correct? zy ∥ wx ∠z ≅ ∠y and ∠w ≅ ∠x zv ≅ vy and wv ≅ vx ∠z ≅ ∠x and ∠w ≅ ∠y

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585