Question

The extremities of a diagonal of a parallelogram are the points $(1,-2)$ and $(-4,3)$. If third vertex is $(-1,0)$. Then the co-ordinates of fourth vertex are :

• A. $(2,1)$
• B. $(-2,-1)$
• C. $(-2,1)$
• D. $noneofthese$

Answer 1

The correct option is A $(2,1)$

$\begin{array}{c}p\left(\frac{-3}{2},\frac{1}{2}\right)\\ \frac{\alpha -1}{2}=-\frac{3}{2}\\ \alpha =-2\\ \frac{\beta +0}{2}=\frac{1}{2}\\ \beta =1\\ \left(2,1\right)\end{array}$