question_answer

If the middle points of the sides BC, CA and AB of the triangle ABC be (1, 3), (5, 7) and (-5, 7), then the equation of the side AB is               

A) \[x-y-2=0\]                               

B) \[x-y+12=0\]

C) \[x+y-12=0\]                          

D) None of these

Correct Answer: B

Solution :

Slope of \[DE=\frac{7-3}{5-1}=1\Rightarrow \] Slope of AB = 1                    Hence equation of AB is\[y-7=(x+5)\Rightarrow x-y+12=0\].