IXL - Perimeter and area: changes in scale (Geometry practice)

Look at this square:

8 cm

If the side lengths are doubled, then which of the following statements about its area will be true?

The new area will be

times the old area.

The new area will be

times the old area.

The new area will be

of the old area.

The new area will be

times the old area.

ref_doc_title.

Learn with an example

question

Look at this square:

5 mm

If the side lengths are doubled, then which of the following statements about its area will be true?

The ratio of the new area to the old area will be

4:1

The ratio of the new area to the old area will be

8:1

The ratio of the new area to the old area will be

16:1

The ratio of the new area to the old area will be

2:1

solution

You can solve this problem without using the measurements given in the diagram.

The original square had this area:

A = s²

The new square will have sides that are 2 times as long. Since the original side lengths were s, the new side lengths will be 2s. Calculate the area:

A	=	(2s)²

	=	4s²

Divide the new area by the original area and simplify.

new area

original area

4s²

s²

Write the result as a ratio.

4 → 4:1

The ratio of the new area to the old area will be

4:1

Looking for more? Try these:

Lesson: Area of circles

Lesson: Perimeter

Lesson: Area of parallelograms

$Confetti$

Excellent!

Now entering the Challenge Zone—are you ready?

Questions
answeredQuestions

Time
elapsedTime

hr	min	sec
00	00	06

SmartScore
out of 100
IXL's SmartScore is a dynamic measure of progress towards mastery, rather than a percentage grade. It tracks your skill level as you tackle progressively more difficult questions. Consistently answer questions correctly to reach excellence (90), or conquer the Challenge Zone to achieve mastery (100)! Learn more

Teacher tools

Work it out

Not feeling ready yet? These can help:

S.1Perimeter

S.2Area of rectangles and squares

S.3Area of parallelograms and triangles

S.9Area and circumference of circles

L.1Understanding ratios

Lesson: Area of circles

Lesson: Perimeter

Lesson: Area of parallelograms

Excellent! You got that right!

Jumping to level 1 of 1

Excellent!