Look at the figure below: Triangle ABC is a right triangle with angle ABC equal to 90 degrees. The length of AC is 5 units, and the length of AB is 4 units. D is a point above C. Triangle ADC is a right triangle with angle DAC equal to 90 degrees and DC parallel to AB. What is the length, in units, of segment CD?

Step-by-step explanation:

Check the sketch of the description of the diagram in the figure below. The figure forms a rectangular shaped figure which was divided into two triangle using the diagonal line AC.

According to the figure AB is known to be parallel to CD i.e AB//CD. Parallel sides are equal sides. Since AB = 4 units then CD will also be equal to 4 units.