Hello, jaynlisa08!

Points P and Q are on opposite sides of a straight tunnel.

A third point R forms a triangle PQR.

S and T are on sides PR and QR repectively such that :

PR= 312m, SR= 116m, ST= 275m, QR= 423m, RT= 287m

Find the length of PQ.In use the Law of Cosines:Code:R o * * * * * * S o * * * * * o T * * * * * * P o * * * * * * * * * * * o Q

. .

In , use the Law of Cosines:

. .

. .

Therefore: . m.