This is the basic and conceptual question from Chapter name- circles
Topic – Angle properties of circles
Chapter number- 15
In the figure given , PQ is a diameter. Chord SR is parallel to PQ.
It is also Given that ∠PQR = 58°,
Now we have to calculate (i) ∠RPQ (ii) ∠STP (T is a point on the minor arc SP)
ICSE Avichal publication
Understanding ICSE Mathematics
Question 7(a)
In ∆PQR,
∠PRQ = 90° (Angle in a semi-circle) and ∠PQR = 58°
∠RPQ = 90° – ∠PQR = 90° – 58° = 32°
SR || PQ (given)
∠SRP = ∠RPQ = 32o (Alternate angles)
Now PRST is a cyclic quadrilateral,
∠STP + ∠SRP = 180o
∠STP = 180o – 32o = 148o