IXL | Perimeter and area: changes in scale

Look at this rectangle:

6 cm

7 cm

If the base is tripled, 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

of the old area.

The new area will be

times the old area.

The new area will be

times the old area.

ref_doc_title.

Learn with an example

question

Look at this rectangle:

8 mm

6 mm

If the height is doubled, then which of the following statements about its area will be true?

The new area will be

of the old area.

The new area will be

times the old area.

The new area will be

times the old area.

The new area will be

times the old area.

solution

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

The original rectangle had this area:

A = bh

The new rectangle will have 2 times the height. Since the original height was h, the new height will be 2h. Calculate the area:

A	=	b(2h)

	=	2bh

Divide the new area by the original area and simplify.

new area

original area

2bh

The new area will be

times the old area.

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?

Teacher tools

Work it out

Not feeling ready yet? These can help:

V.1Perimeter

V.2Area

BB.6Area of circles

BB.5Circumference 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!