△PQR and △SQR are both isosceles triangles on a common base QR such that P and S lie on the same side of QR. If ∠QSR = 60° and ∠QPR = 100°. then find ∠SRP.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 20º.
Given that
△PQR and △SQR are both isosceles triangles on a common base QR
P and S lie on the same side of QR
If ∠QSR = 60° and ∠QPR = 100°
According to the question
SQ = SR, ∠SQR = ∠SRQ = (180° - 60°)/2= 120°/2 = 60°
PQ = PR, ∠PQR = ∠PRQ = (180° - 100°)/2 = 80°/2 = 40°
Hence, ∠SRP = ∠SRQ - ∠PRQ = 60° - 40° = 20°