Curated OER
The Pythagorean Theorem and Classifying Triangles
Through the examination of the relationship between the lengths of the sides of a triangles learners will learn the classification of triangles (acute, right, or obtuse).
EngageNY
Composite Area Problems
The 21st segment in a 28-part series provides learners with area problems involving composite figures. To find the solution, pupils must decide whether to add or subtract areas. The composite figures are composed of quadrilaterals,...
Alabama Learning Exchange
Polygons-Changing Area Versus Changing Perimeter
Investigate the area and perimeter of polygons in this geometry activity. Young geometers use grid paper to draw a quadrilateral and calculate its area and perimeter. They also read The Greedy Triangle to identify the changing shape of...
Curated OER
Finding the Area and Perimeter of Polygons
Seventh graders practice finding the area and perimeter of polygons. In this polygon area activity, 7th graders brainstorm shapes and take a walk to locate shapes. Students record properties of shapes and use various shapes to make...
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...
Curated OER
Ratios for Area and Volume
In this ratios for area and volume worksheet, students solve problems where they find the ratios for problems of shapes dealing with area and volume. Students complete 4 problems.
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
Area of Tangram Pieces
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...
Hotchalk
Triangle Sum Theorem
Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...
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.
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
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.
Willow Tree
Surface Area of Three-Dimensional Figures
Lateral area and surface area are simple concepts, but calculating them is not as easy! Using formulas, learners calculate lateral area and surface area for the same three-dimensional figures. The resource discusses the formula variables...
Curated OER
Algebra/Geometry Institute Summer 2009 - Triangles and the Pythagorean Theorem
Seventh graders find the perimeter and area of triangles. In this finding the perimeter and area of triangles lesson plan, 7th graders find the perimeter and area of triangles given two sides. Students find the missing side...
Curated OER
A Practical Application For Area
First graders investigate the concept of surface area and find the coverage for the surfaces in a building that includes carpet or walls. The application of finding the area is practical using the everyday objects to help them to make...
Curated OER
Special Right Triangles
Using the Pythagorean Theorem to solve for missing angles, learners evaluate right triangles and their properties.
Curated OER
Geometry of Triangles - Week 6
In this triangle worksheet, pupils explore the characteristics of triangles. They find the area of a pentagon, lengths of the sides of a triangle and the area of a quadrilateral. This two-page worksheet contains seven problems.
Curated OER
Geometry: Area, Scale Factor, Circumference
In this geometry worksheet, students solve 10 problems regarding area, scale factors, and circumference. Students, in 3 of the problems, are given the circumference and asked to work backwards to find missing information.
Curated OER
Nets And Surface Area
Upper graders investigate how to find the surface area when using two-dimensional shapes. They conduct an investigation in groups while working sample problems given during class discussion with the teacher. They also review how to...
Curated OER
Perimeter & Area Worksheet I
In this perimeter and area worksheet, students find the perimeter and area of regular polygons. They identify the perimeter and area of polygons such as triangles, trapezoids, circles, rectangles, and parallelograms. Students write the...
Curated OER
Perimeter and Area Worksheet II
For this perimeter and area worksheet, students find the perimeter and area of polygons. They use the proper formula to find the perimeter and area of circles, parallelograms, triangles, and rectangles. Students complete solve ten problems.
Curated OER
Acute Triangles
Learners study acute triangles. They measure angles using a protractor, then classify the triangles as either right, obtuse, or acute. Everyone creates a design for a Navajo rug using only acute triangles.