Let's design Spur gear in Creo Parametric

relations for spur gear:
pressure_angle = 14.5° & 20° (Standard value)
module = reference_dia/no_of_teeth /*module

reference_dia = module*no_of_teeth /*reference_dia
circular_pitch = pi*module /*circular pitch
addendum = module /*addendum
dedendum = 1.25*module /*dedendum
tip_dia = reference_dia+2*addendum /*tip diameter
root_dia = reference_dia2*dedendum /*root_diameter
base_dia = reference_dia*cos(pressure_angle) /*base_diameter
root_fillet = 0.38*module /*root fillet radius
semitopping = 0.1*module
teeth_thickness = circular_pitch/2 /*teeth thckness

clearance = dedendum addendum

Involute equation:
theta = 90*t
angle_ratio = theta/360
S = angle_ratio*pi*base_dia
base_radius = base_dia/2
Xc = base_radius*cos(theta)
Yc = base_radius*sin(theta)
X = Xc+(S*sin(theta))
Y = Yc(S*cos(theta))
Z = 0