How do i "complete the square"? (algebra)

What scale factor was applied to the first rectangle to get the resulting image interior answer as a decimal in the box

Graph y ≥ -x^2 - 1. click on the graph until the correct graph appears.

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?