Interactive
Scholastic

Study Jams! Area of a Triangle

For Students 4th - 6th Standards
Even though there is a wide variety of different triangles in the world, knowing a single equation allows us to find the area of each and every one of them. Follow along with this step-by-step presentation as Zoe clearly models how to...
Lesson Plan
Shodor Education Foundation

Triangle Area

For Teachers 6th - 9th Standards
While the instructional activity focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in...
Lesson Plan
Illustrative Mathematics

Area of a Trapezoid

For Teachers 7th - 9th Standards
Here is a straightforward example of how to apply the Pythagorean Theorem to find an unknown side-length of a trapezoid. Commentary gives additional information on proving that the inside of the trapezoid is a rectangle, but is...
Worksheet
Curated OER

Area of Right-Angled Triangles

For Teachers 3rd - 5th Standards
There's a trick to solving the area of a triangle, and it involves a skill your geometers have already mastered. Help them discover the connection between finding a rectangle's area and finding a right triangle's area as they solve for...
Lesson Plan
EngageNY

Perimeter and Area of Triangles in the Cartesian Plane

For Students 9th - 12th Standards
Pupils figure out how to be resourceful when tasked with finding the area of a triangle knowing nothing but its endpoints. Beginning by exploring and decomposing a triangle, learners find the perimeter and area of a triangle. They...
Lesson Plan
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Curated OER

Areas of Geometric Shapes with the Same Perimeter

For Teachers 7th - 9th Standards
A triangle, square, hexagon, and circle all have a perimeter of one unit. Eighth graders must attempt to find the area of each and arrange them in order from least to greatest areas. A terrific task for applying four different...
Lesson Plan
Curated OER

Finding the Area of an Equilateral Triangle

For Teachers 9th - 11th Standards
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
Lesson Plan
Illustrative Mathematics

Finding Areas of Polygons, Variation 1

For Teachers 5th - 9th Standards
An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...
Lesson Plan
EngageNY

An Area Formula for Triangles

For Teachers 11th - 12th Standards
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
Lesson Plan
Willow Tree

Area of Common Geometric Figures

For Students 8th - 11th Standards
Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
Assessment
Mathed Up!

Area of Sector and Length of Arcs

For Students 9th - 12th Standards
Viewers learn how to apply proportional reasoning to find area of sectors and arc lengths with a video that starts off explaining how to find the areas of circle sectors and the lengths of arcs. Scholars then practice solving problems...
Worksheet
Curated OER

Easy Worksheet: Area of Triangles

For Students 9th - 12th
In this area of a triangle worksheet, students solve 6 graphing problems. Students find the area of a triangle given the three coordinates of the vertices.
Activity
Curated OER

Triangle Series

For Teachers 9th - 12th Standards
Your algebra learners emphasize the"geometric" in geometric series as they use a common ratio between algebraic terms and find that it corresponds to a repeated similarity transformation. 
Lesson Plan
Illustrative Mathematics

Base and Height

For Teachers 5th - 7th Standards
It is easy to find the area of a triangle where the base and the height are given. But in this resource, it is up to your geometers to identify the base and height of the triangle. In fact, your pupils will learn that there are three...
Lesson Plan
Curated OER

Area of Tangram Pieces

For Teachers 3rd - 4th
Mathematicians calculate the area of a tangram piece without using formulas. They use a geometry journal to record activities during this lesson. They make a set of tangrams and use them to compute area. They use...
Lesson Plan
Curated OER

Finding the Area of a Triangle

For Teachers 5th
Fifth graders investigate the area of a triangle. In this geometry lesson, 5th graders practice finding the area of a triangle using the correct formula: 1/2bh.
Lesson Plan
Curated OER

Area of a Triangle

For Teachers 9th - 11th
In this geometry worksheet, students solve problems by finding the area of a triangle. They are given the sides and asked to solve using the Pythagorean Theorem. There are 72 problems.
Lesson Plan
EngageNY

Using Trigonometry to Determine Area

For Students 9th - 10th Standards
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
PPT
Curated OER

Who Wants to Be a Champion: Perimeter, Area, Symmetry

For Teachers 3rd - 5th
Have your learners practice finding the perimeter and area of geometric shapes using this resource. While just a simple review, this could be a wonderful way to solidify the concepts in their minds.
Instructional Video14:56
Corbett Maths

Area under a Graph

For Students 8th - 12th Standards
What? The calculation of area is a linear distance? A short video shows how to use the areas of simple polygons to estimate the area under a graph. Pupils divide the area under a curve into figures to easier calculate the area. Given...
Worksheet
Curated OER

Area of Triangle - Problem Solving 16.4

For Students 5th - 6th
In this area of triangles worksheet, students find the area of each triangle in the word problems. Students complete five problems.
Activity
5280 Math

Triangle Area Patterns

For Teachers 8th - 10th Standards
Combine algebraic and geometric strategies to find solutions. The task asks learners to find the coordinates of a third vertex of a triangle to create a triangle with a specific area. The project is a set of seven problems that...
Interactive
Curated OER

Triangle Problems-Base, Height, and Area

For Students 10th
For this geometry worksheet, 10th graders find the base, height, or area of a triangle. The one page interactive worksheet contains ten questions. Answers and hints are included. 
Lesson Plan
Curated OER

Exploring the Centroid of a Triangle

For Teachers 9th - 12th Standards
Pupils examine the centroid of a triangle as they use Cabri Jr. to construct a triangle and its medians. The dynamic nature of the software allows learners to measure the lengths of the segments in the triangle and conjecture and verify...