Question

The area of the triangle formed by the mid points of sides of the triangle whose vertices are $(2,1)$, $(-2,3),(4,-3)$ is -

• A. $1.5$ sq. units
• B. 3 sq. units
• C. 6 sq. units
• D. 12 sq. units

Answer 1

Answer: (A)

Area of the triangle formed by joining the mid points of the sides of the triangle $=\frac{1}{4}$ (area of the triangle)
$=\frac{1}{4}\times \frac{1}{2}\left|\begin{array}{ccc}2& 1& 1\\ -2& 3& 1\\ 4& -3& 1\end{array}\right|$
$=\frac{1}{4}\times 6=1.5\text{ sq.units }$