Khan Academy
Khan Academy: Area Challenge
Practice solving problems involving triangles, parallelograms, and composite figures. Exercises include decimals, fractions, and word problems. Area of circles is not included. Students receive immediate feedback and have the opportunity...
Other
Nearpod: Circles: Area and Circumference
In this lesson on circles, 7th graders will learn how to find the area and circumference of circles, semicircles, and compound shapes using formulas.
Other
Nearpod: Circles & Pi
In this lesson, 7th graders will learn vocabulary associated with circles and use formulas to find the area and circumference of circles.
PBS
Pbs: Scale City: Scaling Up Recipes and Circles in the Real World
In this video, students visit a small-town festival that features the world's largest stainless steel skillet. In addition to a question about scaling recipes, they also are asked how increasing or decreasing the radius of a circle...
Khan Academy
Khan Academy: Shaded Areas
Find the areas of shaded regions which are combinations of squares, triangles, and circles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Government of Alberta
Learn Alberta: Math Interactives: Exploring Surface Area, Volume, and Nets
Investigate the concepts of area, volume, 3D shapes, and nets using this interactive Learn Alberta math. The solid shapes focused on this exploration include rectangular and triangular prisms, rectangular and triangular pyramids,...
Maths Challenge
Maths challenge.net: Inscribed Rectangle
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles to solve this equal area of inscribed polygons problem.
Texas A&M University
Wtamu Virtual Math Lab: Beginning Algebra: Formulas
This tutorial will show you how using formulas can help you solve problems. Include formulas for various geometric shapes and steps showing how to use them.
The Math League
The Math League: Area and Perimeter
This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.
University of Regina (Canada)
University of Regina: Math Central: Irregular Surface Area Exercise
Students will be engaged by this assignment that has them estimating the areas of irregular surfaces. This includes computing the area of rectangles, triangles, and circles.
University of Cambridge
University of Cambridge: Nrich: The Pi Are Square
Use the formula given for the area of a circle and a square to solve this challenge. This one page website has the solution available for you.
National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
Texas Instruments
Texas Instruments: Math Today Wildfires Nearly Snuffed
Students can use the data to explore the relationship between area and perimeter for rectangles and circles and they will make generalizations about the shape of the rectangle that will produce the smallest perimeter.
Analyze Math
Analyze Math: Polygons Problems
Here are four problems about the area of a regular polygon. Start by finding the area of a hexagon inscribed in a circle of radius 10, and end by proving that as the number of sides of the polygon increases, the area of the polygon...
University of St. Andrews (UK)
University of St. Andrews: James Gregory
This site, which is provided for by the University of St. Andrews, contains information on the mathematician Gregory and his accomplishments.
University of Waterloo (Canada)
University of Waterloo: Cemc: Math Circles: Patterns [Pdf]
This worksheet provides exercises in working with number patterns. Included are questions related to fractals, patterns in exponents, and perimeter and area.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Pi and the Area of Circles
Contains a question pertaining to finding the area of a circle.
Shmoop University
Shmoop: Basic Geometry: Area (Polygon, Triangle, Circle, Square)
The geometry resource investigates the area of polygons, triangles, circles, and squares. Formulas and examples are included.
Shmoop University
Shmoop: Basic Geometry: Area Formulas
The geometry resource investigates the area of polygons, triangles, circles, and squares. Formulas, examples, and practice exercises are included.
Math Open Reference
Math Open Reference: Diameter
A complete reference guide to diameters. It provides definitions, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Illustrative Mathematics
Illustrative Mathematics: G C, G Srt Setting Up Sprinklers
In this task, students must decide where to place sprinklers on a lawn so that the maximum area of the lawn will be watered. To solve it, they must find areas of sectors of circles and use trigonometric ratios to solve right triangles....
Math Planet
Math Planet: Geometry: Parallelogram, Triangles Etc
Resource examines the area of geometric solids through examples and a video lesson. [0:39]
Math Words
Math Words: Right Circular Cylinder
Find a picture of a right circular cylinder here with the formulas for volume, total surface area, and lateral surface area. Site by MathWords.com.
Other
Visnos: Explore Pi
This interactive demonstration shows firstly how pi relates to the circumference of a circle. This is achieved using a regular polygon approximation, the closed polygon is opened to reveal this magical number. The area of a circle is...