Question

In the figure above, O is the centre of the circle such that OM perpendicular AB . If angle ABC =42 degree, find angle AOC and angle DOC. Prove that AOCD is a cyclic quadrilateral. Tell this I will mark you as brainliest​

Answer 1

Answer:

use the tangent formula..........

Answer 2

Step-by-step explanation:

ANSWER

∠ADC=

2

1

∠AOC

(Angle subtended by a chord on mayor area is half of that subtended on center)

∴∠ADC=

2

1

×130=65

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Now, ADCB is cyclic quadrilateral ⇒

Sum of opposite Angles is 180

∘

∴∠ABC+∠ADC=180

∘

∠ABC+65=180

∘

∠ABC=115

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