Below is the graph of a trigonometric function. it has a maximum point at (-pi, 7.7) and a minimum point at (-1/3 pi, -6.7). what is the midline equation of the function? y=?

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?