Jacob takes a sheet of paper and cuts from one corner to the opposite corner, making two triangles. if the piece of paper is 4 inches long and 5 inches wide, how long is the diagonal cut that jacob made? if necessary, round to the nearest tenth.

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?