VSA2 marksYear: 2020MediumCBSE Class 10
circlestangentchordproof
Question
In Fig. 4, AB is a chord of circle with centre O, AOC is diameter and AT is tangent at A. Prove that ∠BAT=∠ACB.

Solution
1
∠BAC=90°−∠BAT ... (i). In △BAC, ∠B=90° (angle in semicircle)
+1 mark2
∴∠BCA=90°−∠BAC. Or ∠ACB=∠BAT (Using (i))
+1 mark