Which of the figures can be formed from the pieces given in the problem figure?

Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (d)
The pieces are one square and two right-angled triangles, each triangle being half of a square cut along its diagonal. Figure (d) is made of these three pieces and nothing else: the square on the left, and the two triangles joined along their slanting sides to make a second square on the right, as shown below in the same colours.
