The vertices B and C of a Δ ABC lie on the line, , such that BC = 5 units. Then the area of this triangle, given that the point A(1, –1, 2) is.

# The vertices B and C of a Δ ABC lie on the line, , such that BC = 5 units. Then the area of this triangle, given that the point A(1, –1, 2) is.

1. A 2. B 3. C
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### Solution: ‘B’, and ‘C’ lies on the line …(i) , , y = 1
Coordinate of D{3 –2, 1, 4 }
= {3 –3, 2, 4 –2}
Line AD & Line 4 is perpendicular to each other
So
3( 3λ – 3) + 2 × 0 + 4( 4λ – 2) = 0
9λ – 9 + 16λ – 8 = 0
λ = Coordinate of Δ = {3λ – 2, 1, 4 λ } Area of ΔABC  AD = = Area of ΔABC = unit square.

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