Perimeter and Unknown Side Lengths

Laura draws two rectangles.

One rectangle has a side that is 2 cm. and another side that is 8 cm.

The other rectangle has a side that is 3 cm. and another side that is 4 cm.

Which rectangle has the greatest perimeter?

• The 2 cm. by 8 cm. rectangle

• The 3 cm. by 4 cm. rectangle

Tim places two regular hexagons side by side as shown to make a new shape Each side measures 6 centimeters. Find the perimeter of his new shape.

• 36 cm.

• 16 cm.

• 60 cm.

• 72 cm.

What are the possible perimeters his rectangle could be?

• 1 in. x 12 in.

• 2 in. x 6 in.

• 3 in. x 4 in.

• All of the above.

What is the perimeter of the triangle?

• 24 cm

• 15 cm

• 120 cm

• 20 cm

Find the unknown side length if the perimeter is 30 cm.

• 5 cm

• 4 cm

• 8 cm

• 10 cm

Squares are equal on all sides. Perimeter is the measure of ALL the way around an object. So, the perimeter of this square would be ... Pick all that apply.

• 5 + 5 + 5 + 5 = 20

• 5 x 4 = 20

• 5 x 5 = 25

• 5 + 5 = 10

What is the perimeter?
(click to show image)

• 20 metres

• 40 metres

• 60 metres

• 200 metres

What is the perimeter of this shape?

• 10 cm

• 16 cm

• 20 cm

• 26 cm

What is the perimeter? (Hint: this is a square with equal sides!)

• 4 in.

• 16 in. 

• 8 in. 

How do you find perimeter?

• Add 2 side lengths

• Add all the side lengths

• Multiply length x width

• Subtract 1 side length from another