Question

In Figure, if $ \angle ABC=20°$, then $ \angle AOC$ is equal to:

A <

• A. $20°$
• B. $40°$
• C. $60°$
• D. $10°$

Answer 1

The correct option is B

$40°$

Calculate the required angle:

According to the given details,

$\angle ABC=20°$

According to the theorem, we know that the angle subtended by an arc at the center of a circle is twice the angle subtended by it at the remaining part of the circle

$\therefore$$\angle AOC=2\times \angle ABC$

$$\begin{gathered} =2\times 20° \\ =40° \end{gathered}$$

Therefore$\angle AOC=40°$.

Hence, the correct answer is option(C) i.e. $40°$