I've got a bone to pick with SE. Let me post a few shots of what we call "daggers."

Khanjars


Sasuke's Blades Zeta


Serpent Elite's Knives


These things are way too big, they're even as long as the Gladiator's "spatha" type sword





Here are some Daggers of the appropriate size:

Mythril Baselards


Vamper's Knives


Mortal Moggle Mogknives


If you were to line these daggers up with the arm, the blades would barely go past the elbow at most.

For another reference, here's the dagger that the Khanjars are modeled from: