plz give me an exact answer, simply fraction or involving pi plzzzz

Compute the integral / f(x)dax, where the graph of f is the red curve given in the following figure. Note: On the graph of f , all points that are relevant for this computation have integer coordinates; the blue line is just for reference and is not the r-axis. 4 Answer fajar = FORMATTING: Give an exact answer. in Mobius, w is written pi