Scale Factor and Scale Drawings

What is the scale factor from triangle ABC to triangle DEF?

• 1/2

• 7/3

• 2/1

• 10/3

Which of the following are scaled copies of the original portrait? Select ALL the apply.

• A

• B

• C

• D

• E

The distance between two cities on a map is 4 inches.  Find the actual distance if the scale on the map is 2 inches = 40 miles.

• 165 miles

• 50 miles

• 80 miles

• 41.25 miles

The two rectangles are scale drawings. What is the measurement of x?

• 21

• 1.25

• 20

• 4

Quadrilateral NDMP was dilated to make N'D'M'P'. What was the scale factor?

• 2

• 3

• 1/3

• 1/2

Which rule would dilate shows a scale factor of 4

• (x, y) → (y, x)

• (x, y) → (x + 4, y + 4)

• (x, y) → (x, -y)

• (x, y) → (4x, 4y)

Match the following dilations by a scale factor of 1/2.

• (5,1)

• (0, -10)

• (3,4)

• (-6,-8)

• (0,0)

• (10,2)

• (0, -5)

• (6,8)

• (-3, -4)

• (0,0)

Answer explanation

Note that 0/2 is still 0

so (0,0) dilated by 1/2 is still at (0,0)

(0,-10) dilated by a 1/2 is at

(0, -5)

Which copies are scale drawings when compared to the original triangle?

• 1, 2, and 3

• 1 and 2

• 2 and 3

• 1

• 2

Jamie made a scale drawing of his apartment building.  The building is 300 ft tall.  He wants his scale to be 1 inch : 10 ft.  How tall should his building be in his scale drawing?

• 25 inches

• 60 inches

• 1/30 inch

• 30 inches

The pair of figures is similar. Find the missing side.

• x = 12

• x = 3

• x = 40

• x = 4