Help me with this question. This is the diagram. And I also include the question. Please help me .The question.
A=16π-8x+8π/4x^2
Find the value of x such that the value of A is minimum. Hence, find the minimum value of A.
I really hope you can help me please

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?