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′?
- (15, 9)
- (9, 12)
- (11, 11)
- (8, 6)
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′?
- (1, 1)
- (9/2, -3/2)
- (2, -1)
- (3, -3)
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?
- (4, 6)
- (2, 2)
- (19, 21)
- (3, 5)
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?
- 6
- 1/6
- 5
- 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
- 21/2 cm
- 7 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?
- 19 cm²
- 48 cm²
- 12 cm²
- 144 cm²
Tala's star triangle has angles 40°, 60° and 80°. A dilation with scale factor 2 is applied. What are the image's angles?
- 42°, 62° and 82°, each plus 2
- 80°, 120° and 160°, each doubled
- 20°, 30° and 40°, each halved
- 40°, 60° and 80°, unchanged
Line ℓ is y = 2x. It passes through Esme's center, the origin. The dilation has scale factor 3. What is the image of ℓ?
- y = 6x
- The same line, y = 2x
- y = 2x + 3
- y = 2x + 6, a parallel line, since dilations move lines
Line m is y = 2x + 1. Jun dilates m by scale factor 3 about the origin. What is the image of m?
- y = 2x + 4
- y = 2x + 3
- y = 2x + 1
- y = 6x + 3
A dilation about corner C sends Zee's corner D to D′. Using the coordinates on the card, what is the scale factor?
- 2
- 4
- 3
- 1/3