L1:1x−1=1y−2=2z−0 Let Q(λ+1,λ+2,λ)PQ=(λ−4,λ−1,λ+3)PQ⋅m=0

⇒⇒λ−4+λ+1,λ+3=03λ=0λ=0
L2:1x−2=1y−0=2z−1 Let R(μ+2,μ,μ+1)PR=(μ−3,μ−1,μ+4)PR⋅n=0μ−3+μ−1+μ+4=0=μ=0
Area of △PQR(A)=21∣PQ×PR∣A=21∣(−4i^+j^+3k^)×(−3i^+j^+4k^)∣A=21∣7(i^+j^+k^)∣i^−4−3j^1−1k^34=7i^+7j^+7k^4 A2=49×3=147