# How do I find the angle between the planes #x + 2y − z + 1 = 0# and #x − y + 3z + 4 = 0#?

##### 1 Answer

Jan 4, 2016

#### Explanation:

To find the angle between two planes, one has to find the angle between normal vectors of these planes.

How to find a normal vector to a plane

**Normal Vectors**

For the **plane 1** ,

For the **plane 2** ,

**Angle between the 2 vectors**