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...
Scholastic
Study Jams! Area of a Triangle
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...
Curated OER
Areas of Geometric Shapes with the Same Perimeter
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 area...
Curated OER
Area of Right-Angled Triangles
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...
Curated OER
Finding the Area of Polygons
Third graders are exposed to finding the area of polygons by decomposing figures and recomposing them into rectangles. This strategy allows children to expand on their prior knowledge of constructing shapes by rearranging parts into...
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
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...
Curated OER
Two Triangles' Area
Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation.
EngageNY
An Area Formula for Triangles
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....
Illustrative Mathematics
Finding Areas of Polygons, Variation 1
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...
Curated OER
Finding the Area of a Triangle
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.
Curated OER
Finding the Area and Perimeter of Polygons
Seventh graders practice finding the area and perimeter of polygons. In this polygon area lesson, 7th graders brainstorm shapes and take a walk to locate shapes. Students record properties of shapes and use various shapes to make a...
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
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 Shapes
In this area of shapes unit, upper graders participate in hands-on problem solving activities to find the formulas for the area of a parallelogram, a triangle, and a trapezoid. They manipulate the geoboard to explore relationships among...
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...
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.
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...
Mathed Up!
Surface Area
Surface area is the sum of the parts. Given the measurements of different prisms, pupils determine their surface areas. Individuals find the area of each surface and figure out the surface area by finding the sum. The video, part of a...
Curated OER
Area
Learners solve and complete four various types of problems. First, they show on the diagram why the area of a triangle is given by a formula. Then, pupils find the area of each triangle and parallelogram illustrated, They also circle the...
Curated OER
Area of Triangle - Problem Solving 16.4
In this area of triangles worksheet, students find the area of each triangle in the word problems. Students complete five problems.
Curated OER
Triangles
This unit enables scholars to apply the rule for area of a triangle (area equals half base times height). They practice multiplication and division strategies as they calculate areas.
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...
Mathed Up!
Area of Sector and Length of Arcs
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...