Dilations from any center, and what a dilation does to lines
Grade 10 Math Worksheet - Building Confidence

Circle the best answer.
Ren dilates a rocket sticker by scale factor 3 about its corner C(2, -1). Another corner D is at (5, 3). Where is D′?
- (8, 6)
- (11, 11)
- (9, 12)
- (15, 9)
Kira shrinks a kite sticker by scale factor 1/2 about its corner C(-2, 4). Another corner D is at (4, -2). Where is D′?
Coordinate grid. Center C(-2, 4) and corner D(4, -2) are marked. The image is not drawn. Coordinate grid. Center C(-2, 4) and corner D(4, -2) are marked. The image is not drawn. Center C and corner D are marked. The image is not drawn. −4 −3 −2 −1 1 2 3 4 5 6 −4 −3 −2 −1 1 2 3 4 5 6 0 C D - (9/2, -3/2)
- (3, -3)
- (2, -1)
- (1, 1)
Luz's boat sticker was dilated by scale factor 3 about its corner C(1, 3). The image corner D′ is at (7, 9). Where was D?
Coordinate grid. Center C(1, 3) and image corner D′(7, 9) are marked. The original is not drawn. Coordinate grid. Center C(1, 3) and image corner D′(7, 9) are marked. The original is not drawn. Center C and image corner D' are marked. The original is not drawn. −1 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10 11 C D' - (3, 5)
- (2, 2)
- (19, 21)
- (4, 6)
First factor 2, then factor 3. Milo dilates a car sticker by 2 about a center C, then dilates the result by 3 about the same C. What single scale factor does the same job?
- 5
- 6
- 1/6
- 3/2
Side AB = 7 cm. Scale factor 3/2. Side AB of Pia's tent flap is 7 cm long. A dilation with scale factor 3/2 is applied. How long is A′B′?
- 14/3 cm
- 17/2 cm
- 7 cm
- 21/2 cm
Image side A′B′ = 18 cm. Scale factor 3. A dilation with scale factor 3 makes side A′B′ of Bo's bus picture 18 cm long. How long was AB?
- 6 cm
- 15 cm
- 54 cm
- 18 cm
Noah's quilt patch is a square with side 4 cm. A dilation with scale factor 3 is applied. What is the area of the image?
Square with side 4 cm (area 16 cm²). Scale factor 3. Square with side 4 cm (area 16 cm²). Scale factor 3. Square with side 4 cm (area 16 cm²). Scale factor 3. 4 cm - 12 cm²
- 48 cm²
- 19 cm²
- 144 cm²
Ari's dilation about the origin has scale factor 3. It sends D(1, 2) to D′(3, 6) and F(2, 1) to F′(6, 3). How does line D′F′ compare with line DF?
Line DF has slope -1 and does not pass through the origin (the center). D′ = (3, 6), F′ = (6, 3). Line DF has slope -1 and does not pass through the origin (the center). D′ = (3, 6), F′ = (6, 3). Line DF has slope -1 and does not pass through the origin (the center). −1 1 2 3 4 5 6 7 8 −1 1 2 3 4 5 6 7 8 0 D'F' D' F' - A line with slope -3, because the dilation multiplies slopes by 3
- A line that crosses DF at the origin
- The same line, because the slope is the same
- A different line, parallel to DF, because DF misses the center
Line m is y = 2x + 1. Jun dilates m by scale factor 3 about the origin. What is the image of m?
Line m: y = 2x + 1, which does not pass through the origin. Scale factor 3. Line m: y = 2x + 1, which does not pass through the origin. Scale factor 3. Line m: y = 2x + 1, which does not pass through the origin. Scale factor 3. −4 −2 2 4 −8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8 9 10 m - y = 2x + 1
- y = 2x + 3
- y = 6x + 3
- y = 2x + 4
A dilation about corner C sends Zee's corner D to D′. Using the coordinates on the card, what is the scale factor?
Center C(1, 1), point D(3, 2), image D′(7, 4). Center C(1, 1), point D(3, 2), image D′(7, 4). x y C(1, 1) D(3, 2) D'(7, 4) - 1/3
- 4
- 2
- 3