Question

The area of the figure formed by the points (-1,-1,1);(1,1,1) and their mirror images on the plane 3x + 2y + 4z + 1 = 0 is

• A. $\frac{5\sqrt{33}}{29}$
• B. $\frac{4\sqrt{33}}{29}$
• C. $\frac{20\sqrt{33}}{27}$
• D. $\frac{20\sqrt{33}}{29}$

Answer 1

The correct option is D $\frac{20\sqrt{33}}{29}$


Req. area $=\Delta PQ{Q}^1=2\Delta PQM=2.\frac{1}{2}.QM.PM$