Question

(20 Points)

In circle P, M^ ADB is 25°.
What is the m^ APB ?
☁︎
A:65
☁︎
B:40
☁︎
C:25
☁︎
D:50
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Answer 1

Given:

In circle P, m∠ADB is 25°.

To find:

The m∠APB.

Solution:

Central angle theorem: According to this theorem, the central angle of an arc is twice of inscribed angle of the same arc.

From the given figure it is clear that the ∠APB is the central angle and ∠ADB is the inscribed angle on the arc AB.

By using the central angle theorem, we get

`m\angle APB=2* m\angle ADB`

`m\angle APB=2* (25^\circ)`

`m\angle APB=50^\circ`

Therefore, the correct option is D.