A wearable electronic device including a wireless communication unit configured to be wirelessly connected to a projector for projecting a stored presentation onto a screen of an external device; a main body configured to be worn by a user; a microphone integrally connected to the main body; a sensing unit configured to detect a bio state of the user wearing the electronic device; a display unit configured to be attached to the main body; and a controller configured to match a voice information input through the microphone with a portion of the stored presentation, and to display a part of the stored presentation that follows the portion of the stored presentation matching the voice information input on the display unit, wherein the controller is further configured to change an output size of the part of the stored presentation that follows the portion of the stored presentation when the bio state indicates the user to be in a tense state.