Question

Construct a $\Delta ABC$ with $AB=5cm$, $\angle A={120}^o$, $AC=7cm$. Construct circumcircle of it. Then measure of radius is :

• A. $5cm$
• B. $4cm$
• C. $6cm$
• D. $12cm$

Answer 1

The correct option is C $6cm$

$\Rightarrow$ Draw a line segment $AB=5cm$.

$\Rightarrow$ Construct an angle of ${120}^{\circ }$ at point $A$.

$\Rightarrow$ Cut off $AC=7cm$

$\Rightarrow$ Join $BC$

$\Rightarrow$ Draw a perpendicular bisector on sides $AB,BC$ and $AC$, which is meeting at point $O$.

$\Rightarrow$ Take $O$ as a center with radius $OA$ and draw a circle.

$\Rightarrow$ We have to measure radius of circumcircle, which is $6cm.$