LA4 marksYear: 2022HardCBSE Class 10
circlestangentdiameterproofbisect
Question
In Figure 1, a triangle ABC with ∠B=90° is shown. Taking AB as diameter, a circle has been drawn intersecting AC at point P. Prove that the tangent drawn at point P bisects BC.

Solution
1
Let tangent at P meet BC at R. PR=RB (tangents from external point R to the circle)... (i)
+1 mark2
∠RPC=∠RCP (proving ∠RPC=∠ABP as angle in alternate segment, and ∠ABP=∠ACP as angles in same segment of circle)
+2 marks4
From (i) and (ii): RB=RC. Hence the tangent at P bisects BC.
+0.5 marks