Area of Figures and Dilations

The point A (8, 12) was dilated to become point A' (2, 3). What was the scale factor?

• ½

• ¼

• 4

• 2

• A
• B
• C
• D

If a shape is dilated by a scale factor of 1/2, what is the resulting perimeter?

• The new perimeter is 1/2 the original

• The new perimeter is 2 times the original

• The new perimeter is 1/4 the original

• The new perimeter is 4 times the original

What is the formula that compares the areas of the image and preimage?

• A' = A x sf

• A = A' x sf

• A' = A x sf²

• A = bh

Suppose the dimensions of a pentagon with an area of 12 in² are tripled. What would the area of the new pentagon be?

• 108 in²

• 36 in²

• 72 in²

• 144 in²

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

• x = 12

• x = 3

• x = 40

• x = 4

If the scale factor is 5, how times larger will the area of the big square be compared to the smaller square?

• 5

• 20

• 25

The area of the larger square is __________ times larger than the area of the smaller square.

• 1/2

• 1

• 2

• 4

A triangle ABC with sides AB = 8, BC = 16, and AC = 17 is dilated to form a triangle with side B'C' = 8. Which of the following statements about the sides of the image of triangle ABC?

• A'B' = 8

  and A'C' = 17

• A'B' = 0

  and A'C' = 9

• A'B' = 4

  and A'C' = 8.5

• Impossible to determine

What is one way to determine how much the area would increase using a scale factor of 3?

• take the scale factor and square it to get 3x3=9

• add all of the sides together then multiply by 3

• multiply the area of the smaller rectangle by 3