Triangle ABC

𝐴
𝐵
𝐶
has vertices point A(2,1)
𝐴
(
2
,
1
)
, point B(4,3)
𝐵
(
4
,
3
)
, and point C(−2,5)
𝐶
(

2
,
5
)
. Find the coordinates of A′
𝐴

, B′
𝐵

, and C′
𝐶

after a dilation with a scale factor of 7 and a center point of dilation at the origin (0,0)
(
0
,
0
)
.(2 points)
A′=
𝐴

=
(,)
B′=
𝐵

=
(,)
C′=
𝐶

=
(,)

1 answer

To perform a dilation of a triangle with a scale factor of \( k \) and a center of dilation at the origin (0, 0), you can use the following formula for the coordinates of the dilated points:

\[ (x', y') = (k \cdot x, k \cdot y) \]

In this case, the scale factor \( k \) is 7. Now we will apply this formula to each vertex of triangle ABC:

  1. For point A(2, 1): \[ A' = (7 \cdot 2, 7 \cdot 1) = (14, 7) \]

  2. For point B(4, 3): \[ B' = (7 \cdot 4, 7 \cdot 3) = (28, 21) \]

  3. For point C(−2, 5): \[ C' = (7 \cdot (-2), 7 \cdot 5) = (-14, 35) \]

Thus, the coordinates after the dilation are:

  • \( A' = (14, 7) \)
  • \( B' = (28, 21) \)
  • \( C' = (-14, 35) \)

So, the final answers are:

  • \( A' = (14, 7) \)
  • \( B' = (28, 21) \)
  • \( C' = (-14, 35) \)