CK-12 Foundation
Ck 12: Interactive Geometry: 17.5 Sine to Find the Area of a Triangle
Learn how to sine to find the area of a triangle.
Khan Academy
Khan Academy: Area of Right Triangles
Find the area of right triangles Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Find Missing Length When Given Area of a Triangle
Find the base or height of a triangle when given the other and the area. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
National Council of Teachers of Mathematics
Nctm: Illuminations: Igd: Area of a Triangle
Use this interactive tool to learn how to find the area of a triangle. Click on "Instructions" for details on how to use this tool. Click on "Explore" for more ideas. [Requires Java.]
Illustrative Mathematics
Illustrative Mathematics: 8.g Two Triangles' Area
For 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...
Illustrative Mathematics
Illustrative Mathematics: 6.g Same Base and Height, Variation 1
Make the following triangles on a geoboard. Remember that the pegs are equally spaced in a square grid. Compare the areas of the triangles. Aligns with 6.G.A.1.
Mangahigh
Mangahigh: Shape: Area of a Triangle Using Trigonometry
Teat your knowledge of determing the area of a triangle using trigonometry.
Illustrative Mathematics
Illustrative Mathematics: 6.g Base and Height
The purpose of this task is to help students understand what is meant by a base and its corresponding height in a triangle and to be able to correctly identify all three base-height pairs. Aligns with 6.G.A.1.
Sophia Learning
Sophia: Understanding the Area of a Triangle
This lesson will explore ways to determine the area of a triangle.
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.
Calculator Soup
Calculator Soup: Equilateral Triangles Calculator
An equilateral triangle is a special case of a triangle where all 3 sides have equal length and all 3 angles are equal to 60 degrees.
Texas Instruments
Texas Instruments: Move Along Little Vertex
In this activity, students use the Geoboard to determine the area of triangles having the same base and same height.
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...
Better Lesson
Better Lesson: Finding the Area of a Trapezoid
Sixth graders find the area of a trapezoid by decomposing it into triangles and using the formula
CK-12 Foundation
Ck 12: Geometry: Applications of the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] In this lesson students use the Pythagorean Theorem to find perimeter and area. Students examine guided notes, review guided practice, watch instructional videos and...
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...
Calculator Soup
Calculator Soup: Isosceles Triangles Calculator
Use this calculator to find the sides, perimeter, area, semiperimeter, and altitude of an isosceles triangle.
Homeschool Math
Homeschool Math: Area of Right Triangles
This lesson presents the idea that the area of any right triangle is exactly half of a certain rectangle, and contains varied exercises for students.
Math Open Reference
Math Open Reference: Polygons
Get the definition and properties of a polygon. Then explore such topics as: 1) types of polygon 2) area 3) Perimeter 4) angles associated with polygons and 5) names of polygons.
Homeschool Math
Homeschool Math: Area of Parallelograms
This instructional activity presents the idea that the area of any right triangle is exactly half of a certain rectangle, and contains varied exercises for students.
That Quiz
That Quiz: Triangulos
These interactive activities are designed to examine the mathematical concepts of length, perimeter, and area. These activities may be used to develop students' understanding of these mathematical concepts.
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.
Vernet -Virtual Education Resources Network
Salon Hogar: Referencia Rapida De Formulas Geometricas
This site provides the user with a useful reference to different geometric forms, their elements, formulas, and areas. Entirely in Spanish.