3933.sagews

RED = (1,0,0)
RANGE = [ x / 100 for x in range(-200,201) ]

show (
    polygon([ (x, sqrt(1-(abs(x)-1)^2)) for x in RANGE ], rgbcolor = RED) +
    polygon([ (x, acos(1-abs(x))-pi)    for x in RANGE ], rgbcolor = RED),
    axes = true
)