∠SRQ : ∠SRT = 4 : 5 = \(\frac{4}{9} : \frac{5}{9}\) [because 4 + 5 = 9] Also, ∠SRQ + ∠SRT = 180° [because RS is a straight line standing on QT at point R] ∴ ∠SRQ = \(180^\circ \times \frac{4}{9} = 80^\circ\) And, ∠SPQ = \(180^\circ - ∠SRQ = 180^\circ - 80^\circ = 100^\circ\) ∴ ∠SPQ = 100° and ∠SRQ = 80°