PLEASE HELP!! Quadrilateral ABCD is inscribed in circle O as shown below.

Which of the following would be used to find the m∠3?

A. 90°+m∠4

B. 180°−m∠1

C. 270°+m∠2

D. 360°−(m∠1+m∠2)

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?