Question

in the figure, O is the centre of the circle and ABN is a straight line. the obtuse angle AOC=X is:128° how?
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Answer 1

Answer:

From the figure, if we draw a straight line from A to C, we get line AC which is a chord of the circle .

Angle subtended by any chord at the centre of a circle is

double than that of the angle subtended by that chord at any point on circumference of the circle.

∴angleAOC = 2.∠ABC

so, angle AOC=72

∘

Step-by-step explanation:

Hope it is helpful to u

Answer 2

Answer:

From the figure, if we draw a straight line from A to C, we get line AC which is a chord of the circle .

Angle subtended by any chord at the centre of a circle is 

double than that of the angle subtended by that chord at any point on circumference of the circle.

∴∠AOC = 2.∠ABC

So ∠AOC = 72∘

therefore option B will be the answer.