BBC
Bbc: Circumference and Area of a Circle
This is where you can pick up some valuable pointers on how to find the circumference and area of a circle. There is also information on how to find the perimeter and area of a semicircle. When you finish working your way through the...
Alabama Learning Exchange
Alex: Circling Around
Students will calculate the diameter, circumference, and ratio of a real world object. Students will create an electronic slideshow to illustrate the process of determining the diameter, circumference, and ratio of these objects.
![Math by Design: Circumference and Area of a Circle [Pdf] Lesson Plan](https://d15y2dacu3jp90.cloudfront.net/images/attachment_defaults/resource/large/FPO-knovation.png "Math by Design: Circumference and Area of a Circle [Pdf] Lesson Plan")
Thinkport Education
Math by Design: Circumference and Area of a Circle [Pdf]
Students will discover how to estimate and measure the circumference and area of a circle.
National Council of Teachers of Mathematics
Nctm: Illuminations: Area of Trapezoids
Investigate how changes in the base and height of a trapezoid affect its area.
Math Open Reference
Math Open Reference: Area of a Square
A complete reference guide to finding the area of a square. It provides definitions, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Geometry Help
Geometry Help: Inscribed Shapes
Explains the basic concept of inscribed shapes with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Area of Geometric Shapes
Explains the basic concept of the area of geometric shapes with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Square Inscribed in a Circle
Explains the basic concept of a square inscribed in a circle with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Perimeter of Geometric Shapes
Explains the basic concept of the perimeter of geometric shapes with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Cuemath
Cuemath: Radius
This reference tool explores the radius of a circle. Provides definitions, solved examples, and practice questions with answers.
Better Lesson
Better Lesson: Exploring Circumference
What is pi, anyway? Students explore the relationship between circumference and diameter by measuring a variety of circles and use it to derive the formula for circumference.
Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
Other
Nearpod: Circles: Area and Circumference
For this lesson on circles, 7th graders will learn how to find the area and circumference of circles, semicircles, and compound shapes using formulas.
George Mason University
Area Formula Lab
In this set of worksheet activities, students will be guided to discover formulas for area of polygonal shapes and circles.
Wolfram Research
Wolfram Math World: Circumference
This site provides the formula for circumference. Links are provided.
Math Is Fun
Math Is Fun: Definition of Circumference
Definition of circumference. Click the "here's more" link to learn more about a circle; its radius and diameter, area, lines, slices and common sectors.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Circunferencia Y Circulo: Longitudes Y Areas
Reinforce your knowledge of the circumference and the area of a circle with these activities. [Requires Java.]
Learning Wave Communications
Learning Wave: Geometry, Section 2
Geometry concepts are briefly discussed at this site, including volume of a cylinder, parallelograms, circles, trapezoids, and triangles. Sample problems and applications are included for practice.
ClassFlow
Class Flow: Polygon Review
[Free Registration/Login Required] This flipchart provides a review of polygons and formulas for calculating perimeter and area in the form of assessment questions.
ClassFlow
Class Flow: Shapes, Area, and Perimeter
[Free Registration/Login Required] Students will begin practice identifying shapes. Then they will practice solving area and perimeter problems, for different shapes.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Circumference
Find a quick, concise explanation of circumference. The formula for finding the circumference of a circle is explained.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Diameter
Find a quick, concise explanation of what the diameter of a circle is. An example is given and clearly explained.
ClassFlow
Class Flow: 12 Squares Investigations
[Free Registration/Login Required] In this lesson students investigate the relationship between meeting points and the perimeter of shapes by joining 12 squares.
ClassFlow
Class Flow: Area
[Free Registration/Login Required] This creative and engaging flipchart explains the area of all kinds of shapes, to include squares, parallelograms, rectangles, triangle, and trapezoids.