Question

Area of the triangle formed by the lines 7x – 2y + 10 = 0, 7x + 2y – 10 = 0 and y + 2 = 0 is

• A. 8
• B. 14
• C. 16
• D. 18/7

Answer 1

Answer: (B)

14

Answer 2

y = $\frac{7}{2}$x + 5

y = $\frac{- 7}{2}$x + 5 ; y =0 x – 2

D = $\frac{1}{2}$

$\left| \frac{(c_{1} - c_{2})^{2}}{m_{1} - m_{2}} + \frac{(c_{2} - c_{3})^{2}}{m_{2} - m_{3}} + \frac{(c_{3} - c_{1})^{2}}{m_{3} - m_{1}} \right|$D =

$\left| \frac{(5 - 5)^{2}}{(7/2 + 7/2)} + \frac{(5 + 2)^{2}}{( - 7/2 - 0)} + \frac{( - 2 - 5)^{2}}{0 - 7/2} \right|$D = $\frac{1}{2}$ | 14 + 14 |

= 14