PQR is an equilateral triangle. MN is drawn parallel to QR such that M is on PQ and N is on PR. If PN = 6 cm, then the length of MN is:

Answer: Option B

∵ ΔPQR ∼ ΔPMN
∵ ΔPQR is equilateral
∴ PQ = PR = QR

So, ΔPMN must be equilateral
So, MN = PN = 6 cm