Arock band has 5 members and 2/5 of the members play string instruments. also 0.4 of the members sing. does the band have the same number of string instruments players as singers? explain

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?