The side QR of an equilateral triangle PQR is produced to the point S in such a way that QR = RS and P is joined to S. Then the measure of ∠PSR is :
The side QR of an equilateral triangle PQR is produced to the point S in such a way that QR = RS and P is joined to S. Then the measure of ∠PSR is :
[A]45°
[B]30°
[C]15°
[D]60°
30°
∠PRQ = 60°
∠PRS = 180° – 60° = 120°
=>∠PSR + ∠RPS = 60°
As RS = PR
∴ ∠PSR = ∠RPS
∴ ∠PSR = $latex \frac{60^{\circ}}{2}&s=1$ $latex = 30^{\circ}$
Hence option [C] is the right answer.