Rectangle pqrs is shown with its diagonals, pr and qs. what type of triangle is △str? right triangleequilateral triangleisosceles trianglescalene triangle

Since you did not provide a diagram, I made one for easier reference. You are asking what kind of triangle is the one shaded in red. Since a rectangle has two sets of congruent sides, their diagonals are also equal. When two diagonals intersect each other, they make 4 congruent sides. Thus, the triangle is an isosceles triangle, since it has two equal sides ST and TR.