Curated OER
Similar Triangles and Proportions
Pupils investigate similar triangles and proportions as they make conjectures about the length of sides of similar triangles. For this lesson, have your class construct similar triangles using Cabri Jr so that they share a common vertex.
Curated OER
Triangle Inequality Theorem
High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...
Curated OER
Constructions Triangles
Learners explore the difference between a construction and a drawing. They focus on various ways to construct different types of triangles. The lesson is an application of Cabri Jr. and reinforces the difference between a constructions...
Curated OER
30-60-90 Right Triangles in Cabri Jr.
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. Young scholars explore the ratios to determine how the...
Curated OER
Areas of States - Estimation
Students estimate the area of states using the formulas for the areas of rectangles, squares, and triangles. In this geometric shapes lesson plan, students divide irregular shaped states into shapes. They use the formulas for areas of...
Curated OER
Napolean Triangle
Students investigate the Napoleon triangle theory. In this polygon lesson, students differentiate between the boundary points, interior and lattice point of a polygon. They apply concepts of equilateral triangles to solve...
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
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.
Curated OER
Area and Perimeter of Polygons
In this geometry worksheet, 10th graders calculate the perimeter and area using the specific formula for that polygon. There are 5 questions with an answer key.
Curated OER
Triangle in the Matrix
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.
Curated OER
Area of Complex Figures
Fifth graders use formulas for calculating areas of squares and rectangles to find area of complex figure, compare their own ideas with their classmates' ideas, and recognize that there are multiple methods for finding area of complex...
Curated OER
Triangle Explorer
Students compute the area of triangles in a computer program. In this measurement lesson plan, students complete 5 easy, 5 medium, and 5 hard problems.
Curated OER
The Centroid of a Triangle
Students familiarize themselves with the construct and measure menus. They demonstrate how to use the Sketchpad Calculator. They draw a triangle and construct the centroid. They shade in each of the small triangles and measure the area.
Curated OER
Isosceles Triangle Theorem
In this geometry worksheet, students differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.
Curated OER
Fish Tanks: Volume and Surface Area
Given a very realistic challenge, your young geometers design residential fish tanks in rectangular and triangular prism shapes. They compute the volume of water each will hold. They also determine the size of plastic covers for each...
Curated OER
Geography: Lengths, Perimeter, and Area of Similar Objects
Sixth graders explore characteristics of similar objects. Using attribute blocks, they explore the ratios of the perimeter, area and side length in similar shapes. They calculate and compare the area of shapes.
Illustrative Mathematics
Painting a Barn
When painting a barn you have to calculate surface area, and that is exactly what this resource is about. Not only will your future home owners calculate the surface area, but also the cost. It is a real-life problem that every that...
Discovery Education
Discovering Math: Exploring Geometry
Apply geometric properties and formulae for surface area and volume by constructing a three-dimensional model of a city. Learners use similar and congruent figures and transformations to create a city of at least 10 buildings. They trade...
Curated OER
Exploring Number and Operation in Secondary Mathematics
Young geometers need a clear understanding of perimeter, volume, and area. This lesson provides a worksheet to help small groups of learners to calculate various measurements of objects and choose the proper units for measurement. It...
Curated OER
Altitude, Median, and Angle Bisector of a Triangle
Learners investigate the special properties of an altitude, a median, and an angle bisector and explore how these special segments divide the area of a triangle. The dynamic nature of Cabri Jr. allows pupils to form and verify conjectures.
Curated OER
Investigating Lengths of Segments in a Triangle
Pupils explore the midsegment of a triangle in the geometry lesson. They draw and measure the segment joining the midpoints of the two sides of a triangle and compare its length to the length of the third side of the triangle. The...
Curated OER
Exploring the Centroid of a Triangle
Pupils examine the centroid of a triangle as they use Cabri Jr. to construct a triangle and its medians. The dynamic nature of the software allows learners to measure the lengths of the segments in the triangle and conjecture and verify...
Curated OER
Classifying Triangles by the Length of the Sides Using Cabri Jr.
Learners follow detailed directions to create triangles on their graphing calculator. In this properties of triangles lesson, they will create triangles on their calculators using the Cabri Jr. application. They then identify three...
Curated OER
Special Segments in Triangles
Students identify important properties of triangles. For this geometry lesson, students differentiate between medians, bisectors and altitudes in a triangle. They identify the properties of these important segments.