Question

The area of the triangle formed by the lines

$7x - 2y + 10 = 0,$ $7x + 2y - 10 = 0$ and $y + 2 = 0$ is.

• A. 8 sq. unit
• B. 12 sq. unit
• C. 14 sq. unit
• D. None of these

Answer 1

Answer: (C)

14 sq. unit

Answer 2

On solving the simultaneous equations, we get the vertices of triangle as (– 2, – 2), (2, – 2) and (0, 5).

Hence, area $= \frac { 1 } { 2 } \left| \begin{array} { c c c } - 2 & - 2 & 1 \\ 2 & - 2 & 1 \\ 0 & 5 & 1 \end{array} \right| = 14$ sq.units.