pie.py 文件源码

def isosceles(t, r, angle):
    """Draws an icosceles triangle.

    The turtle starts and ends at the peak, facing the middle of the base.

    t: Turtle
    r: length of the equal legs
    angle: peak angle in degrees
    """
    y = r * math.sin(angle * math.pi / 180)

    t.rt(angle)
    t.fd(r)
    t.lt(90+angle)
    t.fd(2*y)
    t.lt(90+angle)
    t.fd(r)
    t.lt(180-angle)