### Clue: Trick to snort some drug in (9)
### Answer: CONGRUENT 
 ### Explanation: CON(to trick/to cheat) **plus**(to) GRUNT(to snort, like, say, a pig) **containing**(some … in) E(abbrev. for "Ecstasy", the drug).
Answer: As in "congruent triangles", ones which have the same 3 sides and the same 3 angles as one another.