JAMB - Mathematics (2004 - No. 8)
P, R and S lie on a circle center as shown above while Q lies outside the circle. Find ∠PSO
45o
55o
35o
40o
คำอธิบาย
xo = 35 + 20 (Exterior angle = sum of two interior opposite angles)
x = 55o (∠ at the center twice ∠ at circumference) y = 110o
∠PSO = ∠SPO (base ∠S of 1sc Δ b/c PO = SO)
∴ ∠PSO = (180 - 110)/2
= 35o
x = 55o (∠ at the center twice ∠ at circumference) y = 110o
∠PSO = ∠SPO (base ∠S of 1sc Δ b/c PO = SO)
∴ ∠PSO = (180 - 110)/2
= 35o