COMEDK2012MathematicsStraight Lines
If a vertex of traingle is (3,3) and the mid-points of two sides through this vertex are (2, 3 2 ) and (4, 3 2 ) , then the centroid of the triangle is given by
Options
- A(1,3)
- B(3,0)
- C(3,1)
- D(0,3)
Correct answer
C. (3,1)
Step-by-step solution
Let the vertices of A B C are A(3,3), B (x₁, y₁ ) and C (x₂, y₂ ) . Now, x₁+3 2 =2 and y₁+3 2 = 3 2 x₁+3=4 and y₁+3=3x₁=1 and y₁=0 So, B (1,0) and x₂+3 2 =4 and y₂+3 2 = 3 2 x₂+3=8 and y₂+3=3x₂=5 and y₂=0C (5,0) Hence, centroid = ( 3+1+5 3 , 3+0+0 3 ) = ( 9 3 , 3 3 )=(3,1)