Dilate triangle ABC by a factor of 2 around point A. What are the coordinates of B Q1 (1,0) Q2 (1,-1) Q3 (1,-2) Q4 (2,-4)

Question

asked Oct 28, 2018 17.9k views

2 Answers

Ateev Chopra · Answer 1 · 2018-11-03T09:56:21+0000

Answer:

Option 3: (1,-2)

Explanation:

From the given figure it is clear that the vertices of triangle ABC are A(1,4), B(1,1), C(4,1).

If a figure dilated by the factor k and the center of dilation is point (a,b), then the rule of dilation is

$(x,y)\rightarrow (k(x-a)+a,k(y-b)+b)$

The figure ABC dilated by the factor 2 and the center of dilation is point A(1,4).

$(x,y)\rightarrow (2(x-1)+1,2(y-4)+4)$

$(x,y)\rightarrow (2x-2+1,2y-8+4)$

$(x,y)\rightarrow (2x-1,2y-4)$

The coordinates of B after dilation are

$B(1,1)\rightarrow B'(2(1)-1,2(1)-4)$

$B(1,1)\rightarrow B'(1,-2)$

The coordinates of B after dilation are (1,-2).

Therefore, the correct option is 3.