THE HAnDBook of TECHniCAl AnAlysisThere are two types of corrective triangles, namely:- Contracting/converging: This includes ascending, descending, and symmetri-
cal triangles - Expanding: Sometimes referred to as reverse symmetrical triangles
As a rule, all triangles must subdivide into five waves and at least four waves
must unfold a zigzag‐based pattern. One difference between contracting and
expanding triangles is that wave C is allowed to extend beyond the start of wave
B in an expanding triangle. See Figure 18.10.
Triangles never occur in impulse wave 2 unless it is part of a corrective com-
bination. Triangles are expected to unfold in the following waves:
■ (^) Impulse wave 4
■ (^) Wave B
■ (^) Final wave in a double or triple 3 combination
■ (^) Intervening wave X
Double 3 combinations occur as a W‐X‐Y pattern. Double 3‐based corrective
combinations may occur in the following ways:
■ (^) Flat – X – Flat
■ (^) Flat – X – Triangle
■ (^) Flat – X – Zigzag
■ (^) Zigzag – X – Zigzag
■ (^) Zigzag – X – Flat
■ (^) Zigzag – X – Triangle
See Figure 18.11.
Triple 3 combinations occur as a W‐X‐Y‐X‐Z pattern. Triple 3‐based correc-
tive combinations may occur in the following ways:
■ (^) Flat – X – Flat – X – Flat
figure 18.10 Corrective Triangles.