Find the missing side length of a rectangle

Learning Objectives Define area and perimeter for a rectangle. Recall the formula for the area of a rectangle (Area = length × width). Use division to find a missing side length when the area and one side are known. Use subtraction and division to find a missing side length when the perimeter and one side are known. Explain the relationship between multiplication and division in the context of finding the area of a rectangle. Solve word problems that require finding the missing side length of a rectangle. Imagine you're building a rectangular fence for a puppy, but you've lost one of the measurements! How can you figure it out? 🐶 In this lesson, we will become Rectangle Detectives! You will learn how to use what you already know about area and perimeter, along wi...

TermDefinitionExample RectangleA shape with 4 sides and 4 square corners (right angles). The sides across from each other, called opposite sides, are always equal in length.A door, a book cover, or a tablet screen. Side LengthThe measurement of one of the straight sides of a shape. In a rectangle, we often call them length and width.A rectangle might have a length of 5 inches and a width of 3 inches. AreaThe amount of space inside a flat shape. We measure it by counting how many square units fit inside.If a rectangle is 3 units wide and 4 units long, its area is 12 square units. PerimeterThe total distance around the outside edge of a shape. It's like putting a fence around a yard.For a rectangle with sides of 5 cm and 2 cm, the perimeter is 5 + 2 + 5 + 2 = 14 cm. Fact FamilyA group...

Area Formula A = l \times w The Area (A) of a rectangle is found by multiplying its length (l) by its width (w). The Division Rule for Area \text{Missing Side} = \text{Area} \div \text{Known Side} When you know the total area and one side, you can use division (the opposite of multiplication) to find the other side. Perimeter Rule P = l + w + l + w The Perimeter (P) of a rectangle is found by adding the lengths of all four sides together.