Texas Education Agency
Texas Gateway: Determining Area of Composite Figures
Given composite figures (combinations of rectangles, squares, parallelograms, trapezoids, triangles, semicircles, and quarter circles), students will be able to determine expressions for the area as well as calculate the area of the figure.
National Council of Teachers of Mathematics
The Math Forum: Find the Area of the Shape!
Try to figure out the area of this challenging shape. In order to view the images, you will need to use JavaSketchpad.
Texas Instruments
Texas Instruments: Getting Started With Area Formulas App
Calculate the Area of a Trapezoid This Concept Handheld Software Application reviews the definition and area formula for the rectangle, square, parallelogram, triangle, trapezoid, and circle.
Illustrative Mathematics
Illustrative Mathematics: G C Mutually Tangent Circles
Three circles are mutually tangent. Students are asked to find the total area of the circles plus the area inside where they meet. Students will need to know how to calculate the area of a circle, a sector of a circle, and an equilateral...
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: Pre Algebra: Measure Areas
Demonstrates how to calculate the area of two-dimensional shapes using formulas. Covers parallelogram, triangle, trapezoid, and circle. Includes a video modeling how to find the area of a circle and a triangle. [0:59]
Illustrative Mathematics
Illustrative Mathematics: 8.g Circle Sandwich
Eighth graders are presented with a drawing of a large square inscribed by a circle which is itself inscribed by a second square. They are asked to find the area of the circle outside the smaller square and compare it to the area of the...
Texas Instruments
Texas Instruments: Area Formulas App
Students review the definition and area formula for the rectangle, square, parallelogram, triangle, trapezoid, and circle.
Sophia Learning
Sophia: Estimating the Area of a Circle: Lesson 4
This lesson explains how triangles and parallelograms can be used to estimate the area of a circle. It is 4 of 4 in the series titled "Estimating the Area of a Circle."
Sophia Learning
Sophia: Estimating the Area of a Circle: Lesson 3
This lesson explains how triangles and parallelograms can be used to estimate the area of a circle. It is 3 of 4 in the series titled "Estimating the Area of a Circle."
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...
Varsity Tutors
Varsity Tutors: Hotmath: Review: Area
Find a quick, concise explanation of area and the formulas for different shapes. An example is given to help you understand how find the area of a shape. The area formulas are listed for different types of shapes.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice: Polygons and Area of Plane Figures
Practice using your graphing calculator for measuring and constructing polygons and other plane figures. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under...
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.
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.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
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.
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.
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.
Math Planet
Math Planet: Geometry: Parallelogram, Triangles Etc
Resource examines the area of geometric solids through examples and a video lesson. [0:39]
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.
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.
Wolfram Research
Wolfram Math World: Heron's Formula
This site provides a detailed overview of Heron's Formula. Content includes a definition, example, and formula.