Need help producing triangular waveforms
There is no direct selection possible for a triangular signal voltage source.  

Set the properties of the Voltage source as follows


Choose a VPULSE source as usual
Set the Tr rise time to about 0.49 times the period of the signal
Set the Tf fall time to the same value as the rise
The PW pulse width can be very small ideally can be set to 0.01 times the period.  
Below figure is generic VPULSE waveform. Modifying the timings will change it to triangular wave




You can slightly change or tweak the values. Let me know if you are still stuck.