How to judge is a sine wave which read from oscilloscope

[weschen]

How to judge is a sine wave which read from oscilloscope? Compare to square,triangle,sawtooth wave....,Just check it by the frequency,amplitude,Max Value......? 

[RavensFan]

"Judge is a sine wave" ?   Not very clear English.

Are you trying to decide if a wave is a clean sine wave or something else?  If so,  you could do an FFT on it.  A perfect sine wave would have only have a single peak in the FFT.  All others would have multiple peaks in the FFT.

[weschen]

Thanks,I will try it. I means check the wave is sine wave that read from oscilloscope.