# 4.7 - Perimeter and Area

The student will

• solve practical problems that involve determining perimeter and area in U.S. Customary and metric units.

### BIG IDEAS

• Doctors measure our height to see how tall we have gotten.

• Linear measurement is key when finding area, perimeter, or volume.  If we want to buy a rug, paint a wall, or frame a picture, we have to measure in order to know how much to buy.

• Scientist use linear measurements when collecting data on experiments.

• Measurements also help students to understand the concepts of fractions.  When we are using measurement tools such as a ruler we are practicing how to use fractions on a number line.

### UNDERSTANDING THE STANDARD

• Perimeter is the path or distance around any plane figure.
• To determine the perimeter of any polygon, determine the sum of the lengths of the sides.
• Area is the surface included within a plane figure.  Area is measured by the number of square units needed to cover a surface or plane figure.
• Students should have opportunities to investigate and discover, using manipulatives, the formulas for the area of a square and the area of a rectangle.
• Area of a square = side length × side length
• Area of rectangle = length × width
• Perimeter and area should always be labeled with the appropriate unit of measure.

### ESSENTIALS

The student will use problem solving, mathematical communication, mathematical reasoning, connections, and representations to

• Determine the perimeter of a polygon with no more than eight sides, when the lengths of the sides are given, with diagrams.
• Determine the perimeter and area of a rectangle when given the measure of two adjacent sides, with and without diagrams.
• Determine the perimeter and area of a square when the measure of one side is given, with and without diagrams.
• Solve practical problems that involve determining perimeter and area in U.S. Customary and metric units.

### KEY VOCABULARY

Updated: May 29, 2019