Arthur D. answered 08/28/19
Tutor
4.9
(65)
Forty Year Educator: Classroom, Summer School, Substitute, Tutor
I assume you have a rectangle PQRS or a square PQRS with PR and QS being diagonals.
The opposite sides of a rectangle are congruent and all four sides of a square are congruent.
Therefore RS is congruent to PQ and thus RS=8.