Explanation :
Arrange 4 extra sticks in Alphabet ?Z? and rotate Z then place it inside the square box as given in the below image. If we cut the square into two parts, we get the square into the same shape and area as two equal parts of the square.
Matchstick Image : Solved Answers Divide the Square Matchstick Puzzle
Matchstick Image : Answers Divide the Square Matchstick Puzzle