The maximum number of new regions that are created when we add another line to a configuration of 15 coplanar lines in general position is

A plane with the equation + volume V = 1/6 Vmin = + 12/2 = 1 (a, b, c > 0) together with the positive coordinate planes forms a tetrahedron of abc. Find the minimum value of V among all planes passing through the point P = (7,7,7). (Use symbolic notation and fractions where needed.)

How do you find the distance between two lines that are described by two given points per line, by taking this distance as the distance between two parallel planes? Please show with an example of L1 having points (0, 0, 0) and (2, 0, -1), and L2 having points (1, -1, 1) and (4, 1, 3), and explain each step clearly and in typefont. Thank you!

A closed figure in a plane, determined by 3 or more line segments, is a(n)