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The Martial Arts feature gives a monk the ability to use Dexterity instead of Strength with unarmed strikes and monk weapons. It also gives the monk the ability to make an additional unarmed strike as a bonus action. A monk must be unarmed or wielding only monk weapons to use Martial Arts.
The Ki feature gives a monk the ability to spend one Ki point to use Flurry of Blows, which lets the monk make two additional uarmed strikes as a bonus action.
If a monk is wielding a weapon that is not a monk weapon (ignoring the question of whether it is wise for the monk to do this), can s/he still spend a Ki point to make two additional unarmed strikes as a bonus action? If so, must the unarmed strikes use Strength rather than Dexterity? I believe that the answer to both is yes, but am I missing something?