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The coordinate plane below shows the location of rectangle TUVW.

Rectangle TUVW is to be dilated by a factor of 3, with the center of dilation at the point (1,0).
Drag and drop the correct answers into each box below.

After dilation, the image of vertex T will be located at the point _______.

The length of the image of side TU will be _____ times the length of TU.

The area of the image of TUVW will be _______ times the area of rectangle TUVW.

Answer choices: 3, 6, 9, (0,3), (-6,6), (-8,6)

The coordinate plane below shows the location of rectangle TUVW. Rectangle TUVW is-example-1

1 Answer

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Explanation:

the dilation by 3 with its center at (1, 0) means we need to imagine the direct lines between T and the center, U and the center, V and the center and W and the center, and make them 3 times as long.

that gives the new points.

(1, 0) to T is 2 units up, 3 units left.

3 times as long means 3×2 units up, 3×3 units left (all from the dilation center) :

(-3×3 + 1, 3×2 + 0) = (-8, 6) for new T.

it goes to the left (negative x side) and starts with 1 of (1, 0).

it goes up (positive y side) and starts with 0 of (1, 0).

(1, 0) to U is 1 unit down, 3 units left.

3 times as long means 3×1 unit down, 3×3 units left :

(-3×3 + 1, -3×1 + 0) = (-8, -3) for new U.

it goes to the left (negative x side) and starts with 1 of (1, 0).

it goes down (negative y side) and starts with 0 of (1, 0).

(1, 0) to V is 1 unit down, 2 units right.

3 times as long means 3×1 unit down, 3×2 units right :

(3×2 + 1, -3×1 + 0) = (7, -3) for new V.

it goes to the right (positive x side) and starts with 1 of (1, 0).

it goes down (negative y side) and starts with 0 of (1, 0).

(1, 0) to W is 2 units up, 2 units right.

3 times as long means 3×2 units up, 3×2 units right :

(3×2 + 1, 3×2 + 0) = (7, 6) for new W.

it goes to the right (positive x side) and starts with 1 of (1, 0).

it goes up (positive y side) and starts with 0 of (1, 0).

so, after dilation, the image of vertex T will be at (-8, 6).

the length of the image of side TU will be 3 times the length of TU.

the area of the image of TUVW will be 3×3 = 9 times the area of TUVW.

because for the area 2 lengths are multiplied. each length has the scaling factor of 3, so multiplying them gives the scaling factor 3×3 = 9 for the area.

User Cristian Gutu
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