Thank you to everyone who sent in solutions for this one.
Charlotte , Natasha , Abbie , Adiva and Kristina (Moorgate CP School)
Harriette, Holly and Ellie (The Mount School, York)
Luke (Tattingstone School)
Christina (Marlborough Primary School)

Only the two very best solutions are shown below. They are best because they use all the match- sticks in the triangles and there are exactly four triangles (and only four triangles) in each.

Helen, Lydia and Antonia (The Mount School York)

Marion (Moorgate Primary School) and Daniel (Anglo-Chinese School, Singapore) who did this drawing.