Length is the measurement of how long an object is from one end to the other. It is a fundamental concept in geometry and is often measured in units such as inches, feet, meters, or centimeters.

There are several units used to measure length:

**Inches:**A small unit of length often used for measuring smaller objects.**Feet:**A larger unit of length often used for measuring height or distance.**Meters:**The standard unit of length in the metric system, used in many countries around the world.**Centimeters:**A smaller unit of length used in the metric system, often for more precise measurements.

Length can be measured using tools such as rulers, tape measures, or meter sticks. When measuring, it's important to align the starting point of the object with the 0 mark on the measuring tool and then read the measurement at the end of the object.

It's often necessary to convert between different units of length. Here are some common conversion factors:

- 1 foot = 12 inches
- 1 meter = 100 centimeters
- 1 yard = 3 feet

1. Convert 5 feet to inches.

Answer: 5 feet * 12 inches/foot = 60 inches

2. If a pencil is 15 centimeters long, how many millimeters is it?

Answer: 15 centimeters * 10 millimeters/centimeter = 150 millimeters

3. A rope is 8 yards long. How many feet is this?

Answer: 8 yards * 3 feet/yard = 24 feet

Study GuideMeasurement, Perimeter, and Circumference Worksheet/Answer key

Measurement, Perimeter, and Circumference Worksheet/Answer key

Measurement, Perimeter, and Circumference Worksheet/Answer key

Measurement, Perimeter, and Circumference

Geometry (NCTM)

Use visualization, spatial reasoning, and geometric modeling to solve problems.

Use geometric models to represent and explain numerical and algebraic relationships.

Measurement (NCTM)

Apply appropriate techniques, tools, and formulas to determine measurements.

Select and apply techniques and tools to accurately find length, area, volume, and angle measures to appropriate levels of precision.

Develop and use formulas to determine the circumference of circles and the area of triangles, parallelograms, trapezoids, and circles and develop strategies to find the area of more-complex shapes.

Connections to the Grade 7 Focal Points (NCTM)

Measurement and Geometry: Students connect their work on proportionality with their work on area and volume by investigating similar objects. They understand that if a scale factor describes how corresponding lengths in two similar objects are related, then the square of the scale factor describes how corresponding areas are related, and the cube of the scale factor describes how corresponding volumes are related. Students apply their work on proportionality to measurement in different contexts, including converting among different units of measurement to solve problems involving rates such as motion at a constant speed. They also apply proportionality when they work with the circumference, radius, and diameter of a circle; when they find the area of a sector of a circle; and when they make scale drawings.