Use the image to answer the question.
A coordinate plane with four quadrants shows an x axis capped with arrows and ranging from negative 3 to 12 in 1 unit increments and a y axis capped with arrows and ranging from 15 to negative 4 in 1 unit increments. Points upper A, upper B, upper A prime, and upper B prime are plotted in quadrant 1. A coordinate plane with four quadrants shows an x axis capped with arrows and ranging from negative 3 to 12 in 1 unit increments and a y axis capped with arrows and ranging from 15 to negative 4 in 1 unit increments. Point upper A is plotted as left parenthesis 9 comma 9 right parenthesis and point upper B is plotted as left parenthesis 6 comma 6 right parenthesis. The points are joined by a line that extends beyond the points and is capped with arrows at both ends. Point upper A prime is plotted as left parenthesis 3 comma 3 right parenthesis and upper B prime is plotted as left parenthesis 2 comma 2 right parenthesis. The points are joined by a line that extends beyond the points and is capped with arrows at both ends.
Determine the scale factor used in the dilation of line AB , with a center point of dilation at the origin.
(1 point)
Responses
1 answer
The length of line AB can be calculated using the distance formula:
AB = √((x2 - x1)^2 + (y2 - y1)^2)
where (x1, y1) = (9, 9) and (x2, y2) = (6, 6)
AB = √((6 - 9)^2 + (6 - 9)^2)
= √((-3)^2 + (-3)^2)
= √(9 + 9)
= √18
= 3√2
Similarly, the length of line A' B' can be calculated using the distance formula:
A'B' = √((x2 - x1)^2 + (y2 - y1)^2)
where (x1, y1) = (3, 3) and (x2, y2) = (2, 2)
A'B' = √((2 - 3)^2 + (2 - 3)^2)
= √((-1)^2 + (-1)^2)
= √(1 + 1)
= √2
Therefore, the scale factor used in the dilation is:
3√2 / √2 = 3