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8.03 Other problems with perimeter

Lesson

Are you ready?

Do you remember how to find the perimeter of a rectangle? Let's try this problem to practice.

Find the perimeter of the rectangle shown.

Learn

In this video, we deconstruct and reconstruct a rectangle. If we know the perimeter and one of the side lengths we can work out the other.

Apply

question 1

Find the missing side length of the rectangle shown.

 

Learn

If we know the perimeter of a square, we can find the side length by dividing the perimeter by $4$4. This works because a square has $4$4 equal sides.

Apply

Question 2

Find the side length of the square shown.

 

Remember!

We can find the perimeters of rectangles and squares by either using a formula or finding the sum of their side lengths.

Outcomes

MA.4.GR.2.1

Solve perimeter and area mathematical and real-world problems, including problems with unknown sides, for rectangles with whole-number side lengths.

MA.4.GR.2.2

Solve problems involving rectangles with the same perimeter and different areas or with the same area and different perimeters.

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