Left Toolbar > Math Nodes > Point Vector Length
The Point Vector Length node allows you to calculate the vector length.
On the left toolbar choose Point Nodes > Point Vector Length
Drag the Point Vector Length icon into the Node Graph.
Connect the point Nodes to the vector input.
Connect the Output: result .
vector A POINT type of value.
A POINT type of value.(x,y)
This attribute is exposed as input by default. Right-click the Node to hide this attribute as input and set the point values manually.