< PQR is a right-angled triangle

PR\(^2\) = 24\(^2\) + 10\(^2\)  = 676

PR = \(\sqrt{676}\) = 26cm

PQRTS is a square and PR = 26cm. meaning the remaining sides of the square are 26cm each 

Therefore, the perimeter of PQRST = 26 + 26 + 26 + 24 + 10 = 112cm