In the triangle PQRPQRPQR, the line segment ST ST\,ST is parallel to the base QRQRQR, where S S\,S lies on PQ PQ\,PQ and T T\,T lies on PRPRPR.
PS=8PS = 8PS=8 cm, SQ=4SQ = 4SQ=4 cm, QR=15QR = 15QR=15 cm, PT=6PT = 6PT=6 cm.
Calculate the length of TRTRTR.
Calculate the length of STSTST.