Four cardboard pieces of specific shapes are shown in the following figure:

Which one of the following figures given can be formed by joining these pieces together ?

The correct answer is the fourth option (the fourth figure, represented by the image showing a central region split horizontally into two rectangles with a right triangle on each side).

To determine which figure can be formed by joining the given cardboard pieces, let us first identify the shapes of the individual pieces shown in the question image (image_0.webp):
1. Two identical rectangles.
2. Two identical right-angled triangles.

Now, let us analyze the composition of the figure in the correct option (image_4.webp):
- Central Region: There is a vertical rectangular block in the middle, which is divided horizontally into two equal halves. This horizontal division creates two identical smaller rectangles stacked one on top of the other. These match the two identical rectangles from the given pieces.
- Left Region: On the left side of the stacked rectangles, there is a right-angled triangle with its vertical side aligned with the left edge of the central rectangles, and its hypotenuse facing outwards to the left.
- Right Region: On the right side of the stacked rectangles, there is another right-angled triangle with its vertical side aligned with the right edge of the central rectangles, and its hypotenuse facing outwards to the right.

By joining the vertical sides of the two right-angled triangles to the left and right edges of the stacked rectangles, we form a perfect parallelogram. This composition utilizes exactly the four cardboard pieces (two rectangles and two right-angled triangles) without any overlapping or gaps, proving that the fourth figure is the correct combination.