Opposite
Step-by-step explanation:
Opposite sides of a rectangle are the same length (congruent).
The angles of a rectangle are all congruent (the same size and measure.)
A 90 degree angle is called a "right angle." So, a rectangle has four right angles.
Opposite angles of a rectangle are congruent.
Opposite sides of a rectangle are parallel.
The diagonals of the rectangle are also congruent.