Prove that the diagonals of a rectangle bisect each other.
the midpoint of ac is

We choose D.

Step-by-step explanation:

Let the midpoint is O

We will use Angle-SIde-Angle principle to prove that the diagonals of a rectangle bisect each other.

Have a look at the two triangles: AOB and DOC, they are congruent because:

So we can conclude that: OB = OB  when two triangles: AOB and DOC are congruent.

Similar, apply for the two triangles: AOD and BOC are congruent so we have OA = OC .

=> It proves that the point O simultaneously is the midpoint and intersection point for the diagonals.

=> The midpoint of AC is ( , ) = (a, b), we choose D.