Someone solve this please

What is the approximate total length of iron edging needed to create the square frame and the two diagonals?

The circumference of a circle is 5 pi cm. what is the area of the circle?

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.