What is the length of bd , given that figure abcd is a rectangle and ac = 26?

Rectangle is a four sided shape with  straight sides, interior angles of 90 degrees and what’s important for this question : opposite sides with equal length.

In the ABCD rectangle, opposite sides are AD and BC, which means their length is the same  AD=BC and AC and BD , AB=CD. The diagonals  all have same length in a rectangle. This means that the length of the diagonal BD is the same as the length of the diagonal AC, and BD=26cm. (Solution A)