FAMERP/2020 Dois cubos idênticos, de aresta igual a 1 dm, foram unidos com sobreposição perfeita de

(FAMERP/2020) Two identical cubes, with edges equal to 1 dm, were joined by perfectly overlapping two of their faces. P is a vertex of one of the cubes, Q is a vertex of the other cube, and R is a vertex shared by both cubes, as shown in the figure. The area of ​​the triangle with vertices P, Q, and R is equal to: a) √6/2 dm² b) √6/3 dm² c) √3/2 dm² d) √6/6 dm² e) (2√3)/3 dm²