1. The points P, (1,2,3), P₂ (2, 1, 2), P, (3, 0, 1), P4 (5, 2,7) are the vertices of a plane quadrilateral find the Coordinates of the midpoints of the sides. What kind of quadrila- teral do these four mid paints form? 2. Given the set S= {(x, y, z): x² + y² +2² = 1}.] L Find the points of SAL where I is the line passing through the origin and having direction numbers 2, 1,3 3. Determine whether or not the three given points lie on a line A (3, 1,0), B (2,2,2), C (0,4,6)