I'm trying to join the attributes from the polygon layers shown on the images.
The result I'm looking for is one layer that contains the square and the attributes of both triangles: the triangles are perfectly overlapped with the square.
I've tried to use "Join attributes by location" but the output layer is not what I'm looking for as it contains two overlapped squares one for each triangle.
Also, I've tried to intersect the layers but the result are two triangles and to join the vectorial layers but the result is again two triangles.