The upper part is divided into a semicircle with a diameter of 6, and the lower part is a sector with a radius of 6 and a central angle of 60 degrees.
So shadow area = sector area+semicircle area-semicircle area = sector area
=60/360πr2= 1/6*π*6*6=6π
8. The coordinate of point P is (x, 0).
The distance from point p to AB is
d = │(√3/3)x+√3│/√(√3/3)？ +(- 1)? )=│(√3/3)x+√3│/(2√3/3)
If the circle p intersects a straight line, d < 1, i.e.
│(√3/3)x+√3│/(2√3/3)< 1
│(√3/3)x+√3│