This small macro create a line giving as an argument the XYZ coordinates, length, and angle

Macro_Line_Length.FCMacro

# -*- coding: utf-8 -*-
# créer une ligne avec une coordonnée une longueur et un angle sur le plan X Y
# create line with coordinate length and angle to plane X Y
import FreeCAD, FreeCADGui, Draft
from math import cos, sin, radians
#from FreeCAD import Base
 
def line_length(x1 = 0.0, y1 = 0.0, z1 = 0.0, length = 10.0, angle = 0.0):
    x2 = x1 + (length * cos(radians(angle)))
    y2 = y1 + (length * sin(radians(angle)))
    z2 = z1 #+ ()
    Draft.makeWire([FreeCAD.Vector(x1,y1,z1),FreeCAD.Vector(x2,y2,z2)])
 
x1 = 0.0          # Edit coordinate x1 origin
y1 = 0.0          # Edit coordinate y1 origin
z1 = 0.0          # Edit coordinate z1 origin
length = 50.0       # Edit length
angle  = 45.0       # Edit angle plane XY
 
#line_length(x1, y1, z1, length, angle)