The amount of tears in the room (denoted by tt t t ) can be defined as a function of the number of people present in the room (denoted by PP P P ), the number of chopped onions in the room (denoted by OO O O ), and the deliciousness of the onions (denoted by DD D D ) using this formula

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?