Shodor Education Foundation
Triangle Area
While the lesson plan 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 in half; can...
EngageNY
Perimeter and Area of Triangles in the Cartesian Plane
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 then...
Education Development Center
Finding Triangle Vertices
Where in the world (or at least in the coordinate plane) is the third vertex? Given two coordinate points for the vertices of a triangle, individuals find the location of the third vertex. They read an account of fictional...
5280 Math
Triangle Area Patterns
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 helps...
Mathematics Assessment Project
Solving Problems with Circles and Triangles
After completing a task involving examining the ratio of areas of triangles and circles in a given figure, scholars examine sample responses to identify other strategies they could use to solve the problem.
Curated OER
Triangle Series
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.
Virginia Department of Education
Area and Perimeter
Develop a strategy for finding the area and perimeter of irregular figures. Building on an understanding of finding area and perimeter of rectangles and triangles, learners apply the same concepts to composite figures. After practicing...
Curated OER
Finding Area of Similar Figures
Students explore the concept of finding area of similar figures. In this finding area of similar figures lesson, students use pattern blocks to construct similar figures. Students trace their construction and find the area. Students...
EngageNY
Perimeter and Area of Polygonal Regions Defined by Systems of Inequalities
When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...
Curated OER
Finding the Area of an Equilateral Triangle
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...
EngageNY
Using Trigonometry to Determine Area
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...
Alabama Learning Exchange
Triangle Area: No Height? Use the Sine
No height? No problem! Learners use their knowledge and a little help from GeoGebra to develop the Law of Sines formula. The Law of Sines helps to determine the height of triangles to calculate the area.
EngageNY
Perimeter and Area of Polygonal Regions in the Cartesian Plane
How many sides does that polygon have? Building directly from lesson number eight in this series, learners now find the area and perimeter of any polygon on the coordinate plane. They decompose the polygons into triangles and use Green's...
EngageNY
Real-World Area Problems
Not all structures take the shape of a polygon. The 21st lesson in a series of 29 shows young mathematicians they can create polygons out of composite shapes. Once they deconstruct the structures, they find the area of the composite figure.
Radford University
Finding the Largest Possible Area
If you want a bigger garden, here's a task for you. Given the perimeter of a triangular garden, scholars determine the largest possible area. They then generalize their findings and extend the idea to other polygons.
Curated OER
What's My Area?
Students use tiles to find area. In this finding area lesson, students explore how to use square tiles to make shapes, then look at how they can be used to measure area. Students then explore how an area can be covered with different...
Curated OER
Unit Squares and Triangles
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle and angle...
Curated OER
Areas of Polygons
Young mathematicians calculate the area of polygons in this algebra lesson. They find the determinant as they calculate the areas for triangles and quadrilaterals. They also use scalar multiplication to find the determinant.
Concord Consortium
Divisions
Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.
Curated OER
Areas of Trapezoids, Rhombuses and Kites
Students calculate the area of different polygons. In this geometry lesson, students find the area for trapezoids, rhombuses and kites.
Curated OER
Area Measures and Right Triangles
Your class will investigate the relationship among different triangles. This geometry lesson, demonstrates how to make a connection between triangles and the Pythagorean Theorem. They identify the missing side or angle of a triangle.
Curated OER
Triangle Midsegment
Learn how to calculate the length and midsegments of triangles. Students differentiate between similar and congruent triangles. They create a spreadsheet with their findings.
Curated OER
Magnetic Fields and Bermuda Triangles
Students map magnetic fields of a magnet using a compass and predict where fields cancel each other to create 'Bermuda Triangles'. In this magnetism lesson, students use a compass to map the magnetic field of a magnet. They explain how...
Curated OER
Complex Area Problems
Students calculate the area of different polygons. In this geometry lesson, students find the area of complex polygons. They solve word problems using rates and distances.