Prove that the angle subtended by an arc at the center is twice the angle subtended by it at
any other point on the remaining part of the circle.
Answers
Answer:
Step-by-step explanation:
An arc PQ of a circle subtending angles POQ at the centre O and PAQ at a point A on the remaining part of the circle.
To prove this theorem we consider the arc AB in three different situations, minor arc AB, major arc AB and semi-circle AB.
Construction :
Join the line AO extended to B.
Proof :
∠BOQ=∠OAQ+∠AQO .....(1)
Also, in △ OAQ,
OA=OQ [Radii of a circle]
Therefore,
∠OAQ=∠OQA [Angles opposite to equal sides are equal]
∠BOQ=2∠OAQ .......(2)
Similarly, BOP=2∠OAP ........(3)
Adding 2 & 3, we get,
∠BOP+∠BOQ=2(∠OAP+∠OAQ)
∠POQ=2∠PAQ .......(4)
For the case 3, where PQ is the major arc, equation 4 is replaced by
☣Hope it helps....❤❤
Answer:
Reflexangle,∠POQ=2∠PAQ
Step-by-step explanation:
Given :Given:
An arc PQ of a circle subtending angles POQ at the centre O and PAQ at a point A on the remaining part of the circle.
To \: \: prove : ∠POQ=2∠PAQToprove:∠POQ=2∠PAQ
To prove this theorem we consider the arc AB in three different situations, minor arc AB, major arc AB and semi-circle AB.
Construction :
Join the line AO extended to B.
Proof :
∠BOQ=∠OAQ+∠AQO .....(1)
Also, in △ OAQ,
OA=OQ [Radii of a circle]
Therefore,
∠OAQ=∠OQA [Angles opposite to equal sides are equal]
∠BOQ=2∠OAQ .......(2)
Similarly, BOP=2∠OAP ........(3)
Adding 2 & 3, we get,
∠BOP+∠BOQ=2(∠OAP+∠OAQ)
∠POQ=2∠PAQ .......(4)
For the case 3, where PQ is the major arc, equation 4 is replaced by
Reflex \: \: angle, \: ∠POQ=2∠PAQReflexangle,∠POQ=2∠PAQ