$\vec{n}$

P: (0, 0, 3)
B: (2, 0, 3)
C: (0, 2, 3)
A: (0, 0, 1)
E = Plane(B, C, A)
d1, j1, j3, j2 = Polygon(A, C, B)
Q = PointIn(E)
v = Vector(P, Q)
d: abs(v)
n: (-1, -1, 1)
N: A + n
u = Vector(A, N)
h = Line(P, n)
F = Intersect(h, E)
w = Vector(P, F)
a: abs(w)
Text1: "d(P, E) = d(P, F) = " + a + ""