Perimeter of Shapes

Perimeter

Module 3 Lesson 1

​How is perimeter different from area? Discuss with your teacher.

We can calculate the perimeter of this square by adding 5+5+5+5=

which equals 20 cm

​Sometimes, the problem will not tell us how long each side is. We must count the spaces to figure it out.

Let's answer some questions.

Have a whiteboard or sheet of paper ready!

Find the perimeter for this square and mark your answer on the next slide.

​

Multiple Choice

What is the perimeter of this square?

• 3 units

• 6 units

• 9 units

• 12 units

What is the perimeter of this triangle?

Be ready to answer on the next slide.

Multiple Choice

What's the perimeter of this triangle?

• 10 cm

• 11 cm

• 12 cm

• 13 cm

What's the perimeter of this triangle?

Be ready to answer on the next slide.

Multiple Choice

What's the perimeter of this triangle?

• 18 inches

• 18 feet

• 18 cm

What's the perimeter of this pentagon?

Be ready to choose your answer on the next slide.

Multiple Choice

What is the perimeter of this pentagon?

• 15 units

• 12 units

• 9 units

• 6 units

Let's challenge ourselves a little bit!

• Not all of the sides are labeled.

• You can still figure out the lengths of the unlabeled sides by looking at the sides on the opposite side.

Multiple Choice

What is the perimeter of this shape?

• 11 inches

• 22inches

LAST QUESTION!

What's the perimeter of this rectangle?

​

Multiple Choice

What's the perimeter of this rectangle?

• 26 cm

• 27 cm

• 28 cm