How to determine the line of intersection of planes

How to determine the line of intersection of planes



In space, two planes can be parallel, coinciding and intersecting. Line intersections two planes This is a straight line, for the construction of which it is necessary to determine two points common to these planes.





How to determine the line of intersection of planes


















You will need




  • - ruler;
  • - a pen;
  • - A simple pencil.




Instructions





1


Construct two non-parallel planes, which at the same time should not coincide with each other, and name them a and b





2


Let the plane b be given by a triangle (ABC). To solve this problem, you need to find two points that are simultaneously common to two planes, and draw a straight line through them line.





3


The plane b can be represented by three straight lines: AB, BC and AC. Point intersections Direct AB with the plane a call the point D.





4


Find the point intersections plane a with a straight line AC and call it the point F. The segment DF will be a line suppression of two planes.





5


A particular case of intersecting planes - mutually perpendicular to the plane. Two intersecting planes will be perpendicular if the third plane (we call it g) is perpendicular to the line intersections given planes (a and b). In other words, the plane a will be perpendicular to the plane b if the plane g is perpendicular to the straight line c (being the line intersections planes a and b), while the straight line a will belong to the plane a, and the line b to the plane b.





6


The first sign of the perpendicularity of the two planes: if the plane b belongs to the straight line b, which in turn is perpendicular to the plane a, then the planes a and b are perpendicular to each other.





7


The second sign of the perpendicularity of the planes: if the plane is perpendicular to the plane andTo the plane a a perpendicular is drawn, which has a common point with the plane b, then this perpendicular lies in the plane b. A straight line passing between perpendicular planes (in this case straight line c), and will be a line intersections given planes.