You can use block "Ramp" from Simulink / Sources. It has 3 parameters: Initial output, Start time and Slope. Slope is a tangent of an angle between your signal and the abscissa axle.
The ramp angle can be adjusted by two ways; amplitudes of signal or signal duration. 'as far as the amplitude is fixed the ramp angle can be adjusted ffrom setting proper stopping
As Mr. Alexander and Mr. Mohammed have suggested yes in Simulink you could adjust slope of ramp. For more clarity you can consider a unit Amplitude signal and try to vary the duration of the signal such that you get desired angle precisely mentioned by Alexander considering tangent of the angle (Amplitude/duration).