Question

The vertices of a triangle are A(–1, –7), B(5, 1) and C(1, 4). The equation of the bisector of the angle ŠABC is–

• A. x + 7y + 2 = 0
• B. x – 7y + 2 = 0
• C. x – 7y – 2 = 0
• D. x + 7y – 2 = 0

Answer 1

Answer: (B)

x – 7y + 2 = 0

Answer 2

We have AB = 10, BC = 5. By bisector property $\frac { 2 } { 1 }$

Ž co-ordinates of D are $\left( \frac { 1 } { 3 } , \frac { 1 } { 3 } \right)$ whence equation of BD is

y – 1 = $\frac { 1 / 3 - 1 } { 1 / 3 - 5 }$ (x – 5) or x – 7y + 2 = 0.