Equation and length of a 3D line.

1. Equation and Length of a 3D Line.
Sharon Liu.
2023/07/24.

3. Two planes, fix the equation in the third plane. To get y = -z + 1, substitute the second equation, into the first equation.
These set of three equations (in the plots), describe a 3-dimensional line. This line, goes through D1 (0, 1, 0), and D2 (2,
3, -2).
The length of this line, is given by l^2 = (x_2-x_1)^2 + (y_2 – y_1)^2 + (z_2 – z_1)^2. This gives you l^2 = (2-0)^2 + (3-1)^2
+ (-2)^2. l = sqrt(4 + 4 + 4) = sqrt(12).