determine whether the polygons are similar. if they are write a similarity statement and find the scale factor

What two criteria are needed for triangles to be similar

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.