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  1. From an external point two tangents to a circle are drawn. The chord passing through the points of contact subtends an angle 72° at the centre. The angle between the tangents is
    1. 36°
    2. 72°
    3. 108°
    4. 144°
Correct Option: C

As per the given in question , we draw a figure of circle in which two tangents are drawn from an external point

From figure , OA = OB = radii of circle
Given , ∠AOB = 72°;
∠OBP = ∠OAP = 90°
In ∠OAB,
∠OAB = ∠OBA
∴ 2 ∠OAB = 180° – 72° = 108°

⇒ ∠OAB =
108°
= 54°
2

∴ ∠PBA = ∠PAB = 90° – 54° = 36°
∴ ∠BPA = 180° – 2 × 36°
∠BPA = 180° – 72° = 108°



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