Lesson Plan
Curated OER

Triangle in the Matrix

For Teachers 9th - 12th Standards
Young mathematicians represent a triangle with a matrix and use the determinant to find the area of three given triangles. Learners also verify the formula for area of a triangle. 
Worksheet
Helping with Math

Geometry: Areas of Triangles

For Students 7th - 9th Standards
For this areas of triangles instructional activity, students observe given polygons. They determine the area of triangles, rectangles and compound figures. This one-page instructional activity contains 5 multi-step problems. This...
Interactive
Curated OER

Area of Figures That Include Circles

For Students 10th - 12th
In this area worksheet, students calculate the perimeter and area of given complex figures.  They determine the area of shaded regions, and find the distance between straight lines.  This one-page worksheet contains 4...
Lesson Plan
Curated OER

Finding Perimeter and Area

For Teachers 3rd - 5th
Geometers find the perimeter and area of rectangles. They discuss the definitions and characteristics of rectangles and squares. In groups, they use yarn to discover the perimeter of squares and rectangles. They count cubes to explore...
Worksheet
Curated OER

Circles: Geometry Review Worksheet

For Students 10th Standards
Tenth graders solve and complete 14 different geometry problems. First, they find the area and circumference of a circle with a given radius. Then, they find the area between a circle and an inscribed equilateral triangle given the...
Lesson Plan
Alabama Learning Exchange

Polygons-Changing Area Versus Changing Perimeter

For Teachers 5th - 8th Standards
Investigate the area and perimeter of polygons in this geometry lesson. 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...
Lesson Plan
Illustrative Mathematics

Same Base and Height, Variation 2

For Teachers 5th - 7th Standards
This is a good model for learners to visualize triangles of the same base and height. They can can begin to comprehend that these triangles will have the same area no matter how the triangle is drawn. It is part of a series of resources...
Lesson Plan
Virginia Department of Education

The Pythagorean Relationship

For Teachers 9th - 11th Standards
Add up areas of squares to discover the pythagorean relationship. Small groups create right triangles with squares along each side. They calculate the areas of each square and notice the relationship. Groups construct other types of...
Lesson Plan
EngageNY

Law of Cosines

For Teachers 11th - 12th Standards
Build upon the Pythagorean Theorem with the Law of Cosines. The 10th part of a 16-part series introduces the Law of Cosines. Class members use the the geometric representation of the Pythagorean Theorem to develop a proof of the Law of...
Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve and complete 5 various types of problems. First, they solve each of the triangles shown and find the area of each triangle. Then, students find the perimeter and area of the regular...
Interactive
Curated OER

Triangle Problems - Find the Height given the Area

For Students 9th - 12th
In this online math worksheet, learners find the height of 5 triangles given their area. This excellent resource allows the students to check their answers, and to get "hints" should they run into difficulties. A terrific teaching tool!
Lesson Plan
Curated OER

Finding The Area Of Shapes

For Teachers 4th
Fourth graders investigate the concept of computing the area using different shapes. They use prior knowledge in order to devise a formula for a parallelogram. Scaffolding is provided by the teacher to find the formula of area for...
Worksheet
Curated OER

Area and Perimeter

For Students 10th
In this area and perimeter learning exercise, 10th graders solve and complete 18 various types of geometry problems. First, they find the area of a figure shown with consecutive sides perpendicular. Then, students find the area and...
Lesson Plan
Curated OER

Area of Polygons

For Teachers 9th - 11th
In this geometry worksheet, young scholars solve for the area of a triangles given the base and the height. There are 6 questions with an answer key.
Activity
Teach Engineering

Stay in Shape

For Teachers 7th - 9th Standards
Using their knowledge of right triangles, pupils find out how far a ship is from a light house. Class members determine how far around the world a ship would be sailing at a constant speed.
Assessment
Noyce Foundation

Pizza Crusts

For Teachers 6th Standards
Enough stuffed crust to go around. Pupils calculate the area and perimeter of a variety of pizza shapes, including rectangular and circular. Individuals design rectangular pizzas with a given area to maximize the amount of crust and do...
Lesson Plan
Curated OER

Finding Areas of Triangles, Rectangles, and Circles

For Teachers 9th - 10th
Students find the areas of geometric shapes. In this geometry lesson students find and measure the sides, perimeters, and areas of quadrilaterals, triangles, and circles. Students relate the measures to the others by using formulas.
Unit Plan
Mathematics Vision Project

Module 5: Modeling with Geometry

For Students 9th - 12th Standards
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...
Lesson Plan
Virginia Department of Education

Pythagorean Theorem

For Students 8th Standards
Investigate the meaning of the Pythagorean Theorem through modeling. After comparing the area of the square of each side, individuals cut triangles and squares to facilitate the comparison.
Lesson Plan
EngageNY

Applications of the Pythagorean Theorem

For Students 8th Standards
Begin seeing the world through the lens of geometry! Use the 19th installment in a 25-part module to apply the Pythagorean Theorem to solve real-world problems. Individuals sketch situations resulting in right triangles such as the...
Worksheet
Curated OER

Using Trigonometry to Find Area

For Students 11th - 12th
In this Algebra II/Trigonometry worksheet, students use trigonometry to determine the area of a triangle or a parallelogram.  The one page worksheet contains ten problems.  Answers are not provided. 
Lesson Plan
Curated OER

Area of Parallelograms and Triangles

For Teachers 8th - 10th
Learners explain the formula for finding the area of a paralellogram and its relation to the area of a rectangle. Finally, they construct the formula for the area of a paralellogram.
Learning
School Mathematics Project

Resource Sheets

For Students 4th - 8th Standards
This extensive and far-reaching collection of worksheets puts a new twist on many basic concepts. Learners use multiplication to trace a path from one point to another, tile a plane by converting between improper and proper fractions,...
Lesson Plan
Mathematics Assessment Project

Solving Problems with Circles and Triangles

For Teachers 9th - 12th Standards
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.