how to find distance between plane and plane, plane and line, plane and a point using corss product ?

Use the analytic method to decide what type of triangle is formed when the midpoints of the sides of an isosceles triangle are joined by line segments.

Write parametric equations for a cycloid traced by a point P on a circle of radius a as the circle rolls along the x -axis given that P is at a maximum when x=0.

draw the line which start point (1,1,0) and end point (3,4,0)by using parametric equation.