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O is the incentre of ABC and angleA=30^(...

O is the incentre of ABC and `angleA=30^(@)`. Accordingly what is `angleBOC`?

A

`100^(@)`

B

`105^(@)`

C

`110^(@)`

D

`90^(@)`

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The correct Answer is:
To solve the problem of finding angle BOC when O is the incenter of triangle ABC and angle A is given as 30 degrees, we can follow these steps: ### Step-by-Step Solution: 1. **Understand the Incenter**: The incenter (O) of a triangle is the point where the angle bisectors of the triangle meet. It is also the center of the circle inscribed within the triangle. 2. **Identify the Angles**: We are given that angle A = 30 degrees. We need to find angle BOC. 3. **Use the Property of Angles**: The property of the angles related to the incenter states that: \[ \angle BOC = 90^\circ + \frac{\angle A}{2} \] This formula arises because the angles at the incenter are related to the angles of the triangle. 4. **Substitute the Given Angle**: Now, we can substitute the value of angle A into the formula: \[ \angle BOC = 90^\circ + \frac{30^\circ}{2} \] 5. **Calculate the Value**: \[ \angle BOC = 90^\circ + 15^\circ = 105^\circ \] 6. **Final Answer**: Therefore, the angle BOC is: \[ \angle BOC = 105^\circ \]
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