Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.

http://www.corestandards.org/Math/Content/6/G/A/1/

Students use graph paper to estimate the area of multiple triangles and use their data to create a formula.

https://illuminations.nctm.org/lesson.aspx?id=1874

 

Students show the area formula for a triangular region by decomposing a triangle into right triangles

Students move a set of 3 points to play with triangles. The lengths of the sides and area are given, allowing students to explore what happens to the area as the lengths of the different sides or the height of the triangle is changed.

http://www.interactive-maths.com/area-of-a-triangle-ggb.html

 
Sheppard Software Triangle Splat
Review types of triangles to prepare for the triangle area lesson
http://www.sheppardsoftware.com/mathgames/geometry/shapeshoot/triangles_shoot.htm

Mr. Nussbaum Zoo Designer
Practice area & perimeter concepts while creating exhibits for animals in the zoo.
http://mrnussbaum.com/zoo/

TPT is a website for teachers to share resources. There are a range of options for geometry support, including word walls and flash cards. Teachers can support students that understand the prerequisite knowledge in another language by posting the relevant math vocabulary for reference. Many ESL students in general benefit from visual references as much as possible. Terms to focus on for this lesson would be area, triangle, right triangle, base, height, length, width, and half. 

 

https://www.teacherspayteachers.com

Students may misidentify the length of one side of the triangle as the height of the triangle. Teachers can emphasize that height is a straight vertical measurement. Using a real world example, like having your height measured at the doctor, can be effective.

 

Many area of a triangle problems have more measurements than needed. It can be difficult for students to pick out which ones are needed to work the problem, especially if the triangle is at an unusual angle. A strong conceptual understanding of the concept that the area of a triangle is half that of its corresponding rectangle will support students in choosing which measurements to use.

 

Students may incorrectly apply what they already know (and probably recently learned) about the area of a rectangle to the triangle. They may multiple the base and height without realizing that the area of the triangle is half. They may also multiply the length of all sides, because this is similar to how one would figure the rectangle. It is important students to have an understanding of why the formula for area of a triangle works in order for them to be consistently successful in implementing it.

Students can watch an example of finding the area of a triangle, either in class or as homework. This lesson also offers interactive work problems that breaks the lesson up into smaller steps: finding the base and height, finding the area of a right triangle, and finding the area of any triangle.Teachers can create practice problems that support the use of these smaller steps as a learning support.

 

https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-triangle/v/example-finding-area-of-triangle

 

Students can do a fun scoot around the room, working with partners to find area of triangles using easy mental math. Keeping the calculations simple allows students more repetitions with the formula, and the scoot offers partner support.

https://www.mathgames.com/skill/7.18-area-of-triangles-and-trapezoids

Students work in groups or individually on real world problems in which they have to measure a triangle to find area. Students can work on a more complicated problem such as using what they know about the area of a triangle to figure out the area of a large star.

 

Students can write their own “area of a triangle” word problem.

Content

Students work in small groups with graph paper to discover the formula for area of a triangle on their own. In-class activity: students work with the formula from the other direction by using given areas to find the triangle. 

Teachers can provide varying levels of support within the problems as needed. For example, using dashed lines to represent the corresponding rectangles in diagrams. Students can continue to use mathematics supports such as writing out multiplication families as needed.

 

Work in a flexible number of problems to work time. Have students work on more interactive projects or on simple practice problems as needed.

Content

Offer a variety of difficulty levels in problems for students to choose from. Students can view different examples of problems by watching short Khan Academy videos.

Number Talk
The area is the entire square is 64 square inches.