In above fig. 2, if D is mid-point of BC, the value of cot y∘cot x∘ is:
In △ACD
cotx∘=ACCD.........(i)
In △ACB
cotY∘=ACCB.........(ii)
Now D is the midpoint of BC
⇒BC=2CD
Dividing (ii) by(i)
⇒coty∘cotx∘=ACCDACCB=CBCD=CB2CB=12
So option D is correct.