Question

Let $A=(-4,0)$, $B=(-1,4)$. C and D are points which are symmetric to points A and B respectively with respect to y-axis, then the area of the quadrilateral ABCD is?

• A. $8$ sq. units
• B. $12$ sq. units
• C. $20$ sq. units
• D. $10$ sq. units

Answer 1

The correct option is C $20$ sq. units

As the point are symmetric to y-axis i.e. $C(4,0)$ and $D(1,4)$

As it a trapezium, Area = $\frac{1}{2}\times height\times \text{sum of parallel sides}$

$BD=2,AC=8,Height=4$

Area = $\frac{1}{2}\times 4\times (8+2)$

$⟹20\text{sq.units}$