# Proving that a line is perpendicular to one planeProving that a line is perpendicular to one plane .

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There is a number of approaching ways in order to prove that a line is perpendicular to a plane (P):

-if a line d1 is perpendicular to another line d and d belongs to (P) => d1 is perpendicular to (P), too.

- d is parallel to another line d1 and d1 is perpendicular to (P), so d is perpendicular to (P), too.

- d is perpendicular to a plane (Q) and the plane (Q) is also parallel to (P), so d is perpendicular to (P), too.

- there are 2 concurrent lines, a and b, that are located in the plane (P), d is perpendicular to a and d is perpendicular to b, so d is perpendicular to (P), too.