The Vertices of ABC are point A(1,2), B(4,6), C(-4,12). Which of the following is true?
a) ABC is not a Right ∆
b) It is a right ∆ with right angle at C
c) It is a right ∆ with right angle at B
d) It is a right ∆ with right angle at A

• for right angled triangle, product of the slopes of 2 sides must be equal to -1.
  here, slope of line CA= (y2-y1)/(x2-x1) = -2. Similarly slope of line AB= 4/3 And slope of line CB= -3/4.
  See here that the product of slope of lines AB and CB = -1.
  Hence the triangle is right angled at B.
• 13 years agoHelpfull: Yes(6) No(0)
• AB=5
  BC=10
  CA=125^1/2
  AB^2 + BC^2 =CA^2
  so B is right angle
• 13 years agoHelpfull: Yes(3) No(0)
• a
• 13 years agoHelpfull: Yes(0) No(3)
• a)
• 13 years agoHelpfull: Yes(0) No(2)
• d
• 13 years agoHelpfull: Yes(0) No(1)
• ans d
  we can find the distance between 3 points and can prove it with hypotnuse theorem
  AB=5
  BC= 10
  CA=(5^2+10^2)^.5
• 13 years agoHelpfull: Yes(0) No(1)
• distance between pt AB=5, BC=10, CA=5*ROOT5;
  AB^2+BC^2=CA^2;
  SO IT IS RIGHT TRIANGLE WITH RIGHT ANGLE AT B;
  SO CORRECT ANSWER IS OPTION C
• 9 years agoHelpfull: Yes(0) No(0)