# How can you tell if a line is parallel to a plane?

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## How can you tell if a line is parallel to a plane?

A line is parallel to a plane if the direction vector of the line is orthogonal to the normal vector of the plane. To check whether two vectors are orthogonal, you can find their dot product, because two vectors are orthogonal if and only if their dot product is zero.

## Can a line and a plane be parallel to each other?

In Geometry, a plane is any flat, two-dimensional surface. Two planes that do not intersect are said to be parallel. Parallel planes are found in shapes like cubes, which actually has three sets of parallel planes. But a line and plane can be parallel to each other and two planes can be parallel to each other.

**How do you verify if a line is on a plane?**

Find two points on your line and determine whether they satisfy the equation of your plane. If both points on the line satisfy the plane equation, the line is in the plane. If only one point satisfies the plane equation, the line intersects the plane but doesn’t lie in it.

### How do you show a plane contains a line?

Condition for a line to lie in a plane

- We observe that a straight line will lie in a plane if every point on the line, lie in the plane and the normal to the plane is perpendicular to the line.
- Here, ( x1, y1, z1 ) = (3, 4, −3) and direction ratios of the given straight line are (a,b, c) = (−4, −7,12) .

### What if two planes are parallel?

In general, if two planes are parallel, then that means their normal vectors, 𝐧 one and 𝐧 two, are equal to one another to within a constant value. If the planes are not parallel, then they may be perpendicular. The condition for that is that the dot product of 𝐧 one and 𝐧 two equals zero.

**How do you tell if a line is on a plane?**

## How do you show that a line is perpendicular to a plane?

A line is perpendicular to a plane when it extends directly away from it, like a pencil standing up on a table. It can’t point anywhere else but directly away from the table. When a line is perpendicular to two lines on the plane (where they intersect), it is perpendicular to the plane.

## Do two planes either intersect or are parallel?

Two lines must either intersect or be parallel. In a plane, two lines perpendicular to the same line are parallel.