Question

Construct $△ABC$ in which $AB=BC=6cm$ and $\angle B={80}^{\circ }$. Locate its incentre and draw the incircle.

Answer 1

Steps for construction:
Step 1: Draw the $△ABC$ with $AB=6cm,\angle B={80}^{\circ }$ and $BC=6cm$.
Step 2: Construct the angle bisectors of any two angles ( $A$ and $B$ ) and let them meet at I. Then I is the incentre of $△ABC$.
Step 3: Draw perpendicular from I to any one of the side $\left(AB\right)$ to meet $AB$ at $D$.
Step 4: With I as centre and ID as radius draw the circle. This circle touches all the sides of the triangle internally.
Step 5: Measure of In-radius $=1.9cm$.