In the first quadrant x≥0, y≥0, so the graph is simply y = |x2 - 4x| which is basically the parabola x2 - 4x with the part lying below the x axis reflected up.
In the second quadrant, x<0, y≥0, so the graph is y = |x2 + 4x|
In the third quadrant, x<0, y<0, so the graph is -y = |x2 + 4x| i.e. y=-|x2 + 4x|.
And in the fourth quadrant, x≥0, y<0, so the graph is -y = |x2 - 4x| i.e. y = -|x2 - 4x|.
Hence, the required graph is
So the required area is 4 times
\int_0^4 (4x-x^2)\ \mathrm dx
i.e 4 323 = 1283
The number of tangents is obviously 4 which could be drawn from (8,0).