Understanding Perimeter

In this video, Mr. J explains how to find the perimeter of various shapes, including a right triangle, parallelogram, regular pentagon, and a composite shape. He demonstrates the process of adding side lengths to calculate the perimeter and emphasizes that the order of addition does not affect the result. The video includes four examples to illustrate these concepts, providing a clear understanding of how to determine the perimeter of different geometric figures.

What is the perimeter of a shape?

• The distance around the outside of a shape

• The volume of a shape

• The diagonal length of a shape

• The area inside a shape

How do you find the perimeter of a right triangle with sides 17 ft, 8 ft, and 15 ft?

• Add the lengths of the sides

• Divide the total length by 3

• Subtract the smallest side from the largest

• Multiply the lengths of the sides

If a parallelogram has sides of 7 y and 11 y, what is its perimeter?

• 40 yards

• 18 yards

• 25 yards

• 36 yards

Does the order of adding side lengths affect the perimeter of a shape?

• Yes, it changes the perimeter

• No, but only for regular shapes

• No, the order does not matter

• Yes, but only for triangles

What is the perimeter of a regular pentagon with each side measuring 33 cm?

• 132 cm

• 99 cm

• 150 cm

• 165 cm

How can you calculate the perimeter of a regular pentagon?

• Multiply the length of one side by 5

• Divide the total length by 5

• Subtract the length of one side from the total

• Add the lengths of all sides

When calculating the perimeter of a composite shape, what should you be careful about?

• Only add the longest sides

• Include all sides without repetition

• Ignore the smallest sides

• Add only the visible sides

What is the perimeter of a composite shape with side lengths 10 m, 4 m, 6 m, 10 m, 6 m, 4 m, 10 m, and 18 m?

• 60 meters

• 72 meters

• 68 meters

• 50 meters

Why is it important not to count any side lengths twice when finding the perimeter of a composite shape?

• It will make the perimeter too small

• It is only important for regular shapes

• It will make the perimeter too large

• It will not affect the perimeter

What is the final step in finding the perimeter of any shape?

• Add all the side lengths

• Subtract the smallest side

• Divide the total length by the number of sides

• Multiply the longest side by the number of sides