Hi, my name is Marija, and today I'm gonna tell you if adjacent angles of a square are congruent. Yes they are, and actually by definition, all angles of a square are congruent, because in order for an object to be considered a square, each of the angles has to be 90 degrees, and since congruent means that they're equal, that means that all of the angles of a square are actually congruent. So yes, these two adjacent angles are congruent because they're both 90, but so are all the other angles in this square. So all of the angles of a square are 90, therefor they are all congruent to each other, and because it's a square, the sides are actually also all congruent to each other. So in a square, all of the sides and all of the angles are equal to each other.