Using Scale Factors to Find the Area of Scale Drawings

The video tutorial explains how to calculate the scaled area of a figure using a scale factor. It begins by defining a scale factor and demonstrating its effect on the dimensions of a figure. The tutorial then shows that simply multiplying the original area by the scale factor does not yield the correct scaled area. Instead, the scaled area is calculated by multiplying the original area by the square of the scale factor. The video provides examples and derives the formula for scaled area, emphasizing the importance of using the scale factor squared.

What is a scale factor?

• A number that adds to the dimensions of a figure

• A number that subtracts from the dimensions of a figure

• A number that multiplies the dimensions of a figure

• A number that divides the dimensions of a figure

If a rectangle's dimensions are scaled by a factor of 3, what happens to its area?

• The area triples

• The area is multiplied by 9

• The area is divided by 3

• The area remains the same

Why doesn't multiplying the original area by the scale factor give the correct scaled area?

• Because the scale factor is used only once

• Because the scale factor is used twice

• Because the scale factor is squared

• Because the scale factor is cubed

How do you calculate the scaled area of a rectangle?

• Add the scale factor to the original area

• Multiply the original area by the scale factor squared

• Subtract the scale factor from the original area

• Multiply the original area by the scale factor

What is the scaled area of a 1-by-2 rectangle with a scale factor of 8?

• 128 square units

• 64 square units

• 256 square units

• 16 square units

What is a common misunderstanding about calculating scaled areas?

• Thinking the scaled area is the original area added to the scale factor

• Thinking the scaled area is the original area subtracted by the scale factor

• Thinking the scaled area is the original area divided by the scale factor

• Thinking the scaled area is the original area multiplied by the scale factor

Why is it important to use the square of the scale factor when calculating scaled areas?

• Because it only affects the width

• Because it only affects the length

• Because it affects both the length and width

• Because it affects neither the length nor width