Question

If the given figure 'O' is the centre of the circle , then the value of x is

• A. ${90}^0$
• B. ${50}^0$
• C. ${20}^0$
• D. ${40}^0$

Answer 1

The correct option is C ${20}^0$

Here,
$<OBC=<OCB={70}^0$
($\because OB=OC=radiusofacircle$)
Also, $<ACB={90}^0$ (Angle subtended by diameter on circumference of a circle is ${90}^0$)
Now, In $△ACB$
$<A+<C+<B={180}^0$
$\Rightarrow x+{90}^0+{70}^0={180}^0$
$\Rightarrow x={20}^0$