How do you perform the indicated operations and write the answer in form a+bi where a and b are real numbers?

Solve this problem! extra ! 3025/5.5 = a/90.75 / = fraction

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?

I’m really confused and need your assist me with this question i’ve never been taught