Perpendicular Line to a Plane
Definition: A line is a line perpendicular to a plane if and only if the line intersects the plane in a point and is perpendicular to every line in the plane that intersects it at that point.
Use the 
tool to draw a line that is perpendicular to the given plane at point A.
Then use the 
tool to place one point (B) on the line and another point © on the given plane.
Now use the 
tool to draw a line in the plane that goes through point A and the point (B) you added to the plane.
To verify that the perpendicular line that you made earlier does form a right angle like a perpendicular line should, use the 
to measure BAC. If you need to, use the 
tool to move the name of point A and the angle measure around in the diagram so that you can read them clearly.
tool to draw a line that is perpendicular to the given plane at point A.
Then use the tool to place one point (B) on the line and another point © on the given plane.
Now use the tool to draw a line in the plane that goes through point A and the point (B) you added to the plane.
To verify that the perpendicular line that you made earlier does form a right angle like a perpendicular line should, use the to measure BAC. If you need to, use the tool to move the name of point A and the angle measure around in the diagram so that you can read them clearly.