(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not a correct explanation of Assertion (A).
Explanation:
Reason (R):
∴ ar(∆ABC ) =
Thus, reason (R) is true.
Assertion (A):
Area of trapezium =
Thus, assertion (A) is true, but reason (R) does not give assertion (A).