Formulas: Sine: V_RMS=V_peak/√2, V_avg=V_peak×2/π (half-cycle rectified average). Square: V_RMS=V_avg=V_peak (ideal, no transition time). Triangle: V_RMS=V_peak/√3, V_avg=V_peak/2. Crest factor and form factor are shape-diagnostic ratios — a pure sine has crest factor ≈1.414 and form factor ≈1.111; a multimeter's "true RMS" spec matters most for non-sine waveforms like these, since a cheap average-responding meter calibrated for sine waves will misread square or triangle waves.