Discovery Education
Discovery Education: Web Math: Find Out Things About Circles
This WebMath site will assist with finding the radius, diameter, circumference, and area of a circle.
CK-12 Foundation
Ck 12: Area and Perimeter of Trapezoids
[Free Registration/Login Required] Students move points on the trapezoid to get the bases and height in order to determine the area and perimeter.
National Council of Teachers of Mathematics
Nctm: Illuminations: Circle Area
Explore what the relationship the radius has to the area of a circle. Click the instructions to learn how to use this interactive resource and select"Exploration" for more ideas.
Analyze Math
Analyze Math: Geometry Problems on Squares
The geometry tutorial investigates word problems on squares with detailed solutions. Topics included are perimeter and area of a square.
Oswego City School District
Regents Exam Prep Center: Area of Polygons and Circles
A lesson focusing on the area of polygons and the circumference of circles. Engaging, interactive practice worksheet, lesson plan, and related classroom activity complete this lesson.
Analyze Math
Analyze Math: Regular Polygons
The interactive tutorial examines the properties and formulas of regular polygons, inscribed circles, and circumscribed circles.
Khan Academy
Khan Academy: Problem Solving With Area and Circumference of Circles
In this exercise, students practice problem solving the area and circumference of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Khan Academy
Khan Academy: Area and Circumference of Parts of Circles
In this exercise, students practice find the area and circumference, of parts of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Khan Academy
Khan Academy: Practice: Area of a Circle
A practice quiz on calculating the area of a circle. Includes hints.
Khan Academy
Khan Academy: Area of a Circle
Find the area of a circle given its radius, diameter, or circumference. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Area and Parts of Circles
Practice finding the area or circumference of part of a circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Science Struck
Science Struck: A Comprehensive Printable List of Geometry Formulas
Provides a list of area and perimeter formulas for two-dimensional shapes and volume and surface area formulas for three-dimensional solids.
Khan Academy
Khan Academy: Radius and Diameter
Practice problems finding radius and diameter of a circle.
Khan Academy
Khan Academy: Circumference of Parts of Circles
Practice finding circumference of parts of circles.
Khan Academy
Khan Academy: Circumference of a Circle
Practice finding the circumference of a circle.
Khan Academy
Khan Academy: Circumference and Rotations
Practice these problems with circumference and rotations.
Khan Academy
Khan Academy: Area of Parts of Circles
Practice problems finding area of parts of circles.
Khan Academy
Khan Academy: Area and Circumference of Circles Challenge
Try these challenge problems involving area and circumference.
Math Open Reference
Math Open Reference: Circles
A complete reference guide to circles including parts, angles, and arcs. It provides definitions and interactive activities that enhance further explanation.
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
Learners 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.
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.