The video tutorial teaches how to find unknown lengths and widths of rectangles by applying mathematical reasoning to a known area. It begins with a problem involving a frame and a photo, explaining the concept of area as the space inside a closed shape. The tutorial demonstrates how to calculate the area of a rectangle and use mathematical reasoning to determine unknown dimensions. It includes examples of solving for width when given area and length, and concludes with a recap of the lesson's key points.

What is the area of a rectangle that is 2 units long and 6 units wide?

• 14 square units

• 8 square units

• 12 square units

• 10 square units

If a rectangle has a length of 5 inches and a width of 8 inches, what is its area?

• 30 square inches

• 40 square inches

• 35 square inches

• 45 square inches

A rectangle has an area of 42 square inches and one side is 7 inches long. What is the width of the rectangle?

• 6 inches

• 8 inches

• 5 inches

• 7 inches

What mathematical operation can be used to find an unknown side length when the area and one side length are known?

• Multiplication

• Division

• Addition

• Subtraction

If a frame is 5 inches wide, what information do you need to find the length of a photo that fits inside?

• The width of the photo

• The area of the photo

• The perimeter of the frame

• The color of the frame