LA4 marksYear: 2022HardCBSE Class 10
circlestangentsinscribed-circletrianglearea
Question
In Fig. 3, a triangle ABC is drawn to circumscribe a circle of radius 4 cm such that the segments BD and DC into which BC is divided by the point of contact D are of lengths 6 cm and 8 cm respectively. If the area of △ABC is 84 cm2, find the lengths of sides AB and AC.

Solution
1
BF=BD=6 cm
CE=DC=8 cm
Let AF=AE=x cm
+1 mark2
⇒AB=(6+x) cm, AC=(8+x) cm & BC=14 cm
+0.5 marks3
Area of △ABC=21×[p]×r=21×(28+2x)×4=84
⇒14+x=21⇒x=7 cm
+2 marks4
⇒AB=13 cm, AC=15 cm
+0.5 marks