Unit Plan
Mr. Martini's Classroom

Mr. Martini's Classroom: Area of Triangles, Trapezoids & Parallelograms

For Students 3rd - 8th Standards
Students solve for the area of rectangles, squares, triangles, trapezoids, and parallelograms.
Handout
Math Open Reference

Math Open Reference: Area of an Equilateral Triangle

For Students 9th - 10th Standards
Learn about the area of an equilateral triangle with this helpful reference tool. Provides a detailed definition, examples, and an internet activity that enhances further explanation. Includes links to related topics.
Activity
George Mason University

Area Formula Lab

For Teachers 4th - 8th Standards
In this set of worksheet activities, students will be guided to discover formulas for area of polygonal shapes and circles.
Activity
National Council of Teachers of Mathematics

The Math Forum: Find the Area of the Shape!

For Students 3rd - 8th Standards
Try to figure out the area of this challenging shape. In order to view the images, you will need to use JavaSketchpad.
Activity
University of Illinois

University of Illinois: Calculation of Triangle Area

For Students 9th - 10th
Discusses how to find the area of a triangle using Heron's formula and provides interactive examples and problems you can solve.
Lesson Plan
Better Lesson

Better Lesson: Finding the Area of a Triangle

For Teachers 6th Standards
Sixth graders find the area of a triangle using square units and the area formula.
Handout
Wolfram Research

Wolfram Math World: Area

For Students 9th - 10th Standards
Definitions and formulas for the computation of surface areas of triangles, rectangles, and any regular polygon. Helpful links to related pages.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g Two Triangles' Area

For Teachers 8th Standards
In this task, 8th graders are given the dimensions of two isosceles triangles and are asked to compare their areas. They must draw them and use the Pythagorean Theorem and the triangle area formula to solve the problem. Aligns with 8.G.B.7.
Website
Cool Math

Coolmath: Precalculus Basic Formulas to Know

For Students 9th - 10th Standards
This CoolMath resource provides an introduction to some Precalculus formulas.
Whiteboard
ClassFlow

Class Flow: Area of Polygons

For Teachers 6th - 8th Standards
[Free Registration/Login Required] This flipchart provides students with notes and practice with using formulas for finding the area of triangles and quadrilaterals.
Unit Plan
Math Planet

Math Planet: Pre Algebra: Measure Areas

For Students 4th - 6th Standards
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]
Unit Plan
Oswego City School District

Regents Exam Prep Center: Area of a Triangle and Parallelogram Using Trig

For Students 9th - 10th Standards
How can trigonometry be used to find the area of a triangle or parallelogram? Does the triangle need to be a right triangle, and how accurate can the results possibly be? The answers to these questions are found here along with several...
Whiteboard
SMART Technologies

Smart: Area of a Triangle

For Teachers 5th - 8th Standards
This SMART whiteboard activity will help students learn the formula for finding the area of a triangle. Students will practice what they have learned by using examples created for visual and kinesthetic learners.
Activity
Texas A&M University

Wtamu Virtual Math Lab: Beginning Algebra: Formulas

For Students 9th - 10th
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.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Gpe Equal Area Triangles on the Same Base I

For Teachers 9th - 10th Standards
This task is a relatively easy application of the formula for the area of a triangle and the use of parallel lines. Aligns with G-GPE.B.5.
Activity
BBC

Bbc: Area in General

For Students 4th - 7th Standards
You can pick up some valuable pointers on how to find the area of a triangle, rectangle, and other quadrilaterals. When you finish working your way through the pages you can take an on-line "Test Bite," and check your understanding.
Activity
University of Georgia

University of Georgia: Problem Solving With Heron's Formula

For Students 9th - 10th Standards
From the University of Georgia, this tutorial provides exercises and problems using Heron's Formula for the area of a triangle, makes use of several problem representation methods, including a graph.
Handout
Wolfram Research

Wolfram Math World: Heron's Formula

For Students 9th - 10th
This site provides a detailed overview of Heron's Formula. Content includes a definition, example, and formula.
Unit Plan
Varsity Tutors

Varsity Tutors: Hotmath: Review: Area

For Students 9th - 10th Standards
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.
Unit Plan
Shmoop University

Shmoop: Basic Geometry: Area Formulas

For Students 9th - 10th Standards
The geometry resource investigates the area of polygons, triangles, circles, and squares. Formulas, examples, and practice exercises are included.
Whiteboard
ClassFlow

Class Flow: Area of Triangles

For Teachers 3rd - 5th Standards
[Free Registration/Login Required] This flipchart explores the formula for finding the area of a triangle. Examples and hints are given to help students. A video clip is included, showing how to find the height of a triangle, given the...
Lesson Plan
Better Lesson

Better Lesson: Finding the Area Review and Assessment

For Teachers 6th Standards
Sixth graders find the area of rectangles, triangles, parallelograms, and trapezoids by using formulas or by composing into rectangles or triangles.
Unit Plan
Cuemath

Cuemath: Right Angled Triangle

For Students 9th - 10th Standards
Explore and learn about the features and properties of a right triangle in this lesson. Includes examples and practice questions.
Unit Plan
CK-12 Foundation

Ck 12: Trigonometry: Heron's Formula

For Students 10th - 12th
[Free Registration/Login may be required to access all resource tools.] Find the area of a triangle when all three sides are known.