Question

Using ruler and compass only, construct a $\Delta$ABC such that $BC=5$cm and $AB=6.5$cm and $\angle$ABC $={120}^o$. Construct a circum-circle of $\Delta$ABC.

Answer 1

Steps:

1. First draw $BC=5cm.$

2. At $B$, draw an angle of ${120}^o$. Along the direction, mark off $BA=6.5cm$ using compasses.

3. Join $AC$. Thus $△ABC$ is completed.

To sketch the circum-circle, we do the following:

1. Construct the perpendicular bisector of $AB$.

2. Construct the perpendicular bisector of $BC$.

3. Mark the point of intersection of both the perpendicular bisectors as $O$.

4. With $O$ as a center and $OA$ as radius, draw a circle. This is the circum-circle of the $△ABC$.