There are three triangles: an acute, a right, and an obtuse. Sasha took one triangle, and Borya took the two remaining. It turned out that Borya can apply (without overlapping) one of his triangles to the other, and get a triangle equal to Sasha's. Which of these triangles did Sasha take?

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Sasha can cut her triangle into two, equal to Borya's, with one straight line. One end of the cut is located at the vertex of Sasha's triangle, and the other is on the opposite side.

Let's look at the side that the cut intersects. The cut is not perpendicular to this side (otherwise, it would result in two right triangles, which contradicts the condition). Therefore, one obtuse triangle and one acute or right triangle will be formed.

In the first case, Sasha's triangle is a right triangle. An example is shown in the figure.

![](https://cdn.mathpix.com/cropped/2024_05_06_c271881b12104a3b803eg-33.jpg?height=535&width=374&top_left_y=1322&top_left_x=842)

In the second case, Sasha's triangle will have a right or obtuse angle, which contradicts the condition.

## Answer

Right triangle.