If we are going to connect opposite vertices of the isosceles trapezoid then we can only make two diagonals. Because of the intersection of these diagonals, we form 4 triangles. Two of which are congruent. These triangles are those with one side being the isosceles sides of the trapezoid.
The remaining triangles are similar because they have congruent corresponding angles and the ratio of the corresponding sides is equal.
Hence, in this item, it can be said that Selina is correct with her statements.
