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PQRST is a cyclic pentagon and PT is a diameter, then ∠PQR + ∠RST is equal to
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- 180°
- 270°
- 216°
- 144°
- 180°
Correct Option: B
As per the given in question , we draw a figure cyclic pentagon PQRST 
Sum of interior angles of a pentagon = (2n – 4) × 90°
Sum of interior angles of a pentagon = (2 × 5 – 4) × 90° = 540°
If PQ = QR = RS = ST
| ∴ ∠POQ = ∠QOR = ∠ROS = ∠SOT = | = 45° | |
| 4 |
∴ OP = OQ = OR = OS = OT = radii
| ∴ ∠OPQ = | = | ||
| 2 | 2 |
| ∴ ∠PQR + ∠RST = 4 × | = 270° | |
| 2 |
