Curated OER
Investigation: Area of Geometric Shapes
Fourth graders explore geometry by utilizing pattern blocks. In this pattern lesson, 4th graders analyze two separate pattern block shapes and discuss which one is bigger and smaller. Students collaborate in small groups to create...
Improving Measurement and Geometry in Elementary Schools
The Sum of the Interior Angles of a Polygon
Junior geometers discover that polygons can be decomposed into triangles and that the number of triangles can be determined by a rule. Note that the Geometer’s Sketchpad® software is required to carry out all components of this...
Curated OER
Measuring Angles in a Triangle
High schoolers investigate the sum of the measures of the angles of a triangle. They draw a triangle and measure the interior angles. Using Cabri Jr., learners find the sum of the measures of the interior angles. The lesson provides an...
Curated OER
Exploring the Circumcenter of a Triangle
Students construct the circumcenter of a triangle. In this constructing the circumcenter of a triangle lesson, students construct a triangle using Cabri Jr. Students draw perpendicular bisectors of the sides of the triangle. Students...
Curated OER
Investigating Segments in a Right Triangle
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
Curated OER
Congruent Triangles
Students identify properties of triangles. In this geometry instructional activity, students differentiate between similar and congruent triangles. They use the umber of sides to help define the angle of the polygon.
Curated OER
Nested Similar Triangles
Nested triangles have been created so that they share a common vertex and vertex angle. Learners drag the endpoints of the side that is opposite the common angle to discover the conditions that make the nested triangles similar. When...
Curated OER
Circumscribing a Circle About a Triangle
Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...
Curated OER
Triangle Sum Theorem
Teach your class how to solve problems using the triangle sum theorem. For this geometry lesson, students identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the sides around to...
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. Students explore the ratios to determine how the hypotenuse...
Illinois State Board of Education
Geoboard Areas
Middle school geometers determine the area of a shape on a geoboard or dot paper and draw figures that meet given area conditions. Working as a class, they develop and discuss various ways to draw geometric shapes with specified...
Curated OER
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios lesson. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various triangles. The provided...
Curated OER
Midsegments of Quadrilaterals
High schoolers explore the concept of quadrilaterals as they find the midsegments of quadrilaterals using Cabri Jr. on a graphing calculator. They find midpoints, slopes, angles, and distances of lines and angles.
Curated OER
Areas of triangles, trapezoids, and rhombi
Students solve geometry problems. In this area and perimeter lesson, students use formulas to solve problems from the textbook.
Curated OER
Areeas of Parallelograms and Triangles
Twelfth graders are able to deduce the area of polygons by using several methods such as coordinate method. They are able to apply the area of polygons to real life situations. Students apply the Pythagorean Theorem in problem solving...
Curated OER
Review of Triangles
Students investigate the Pythagorean Theorem. In this geometry activity, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.
Curated OER
Review Geometry - Week 8 (Triangles)
In this triangle worksheet, students use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.
Curated OER
Perimeter and Area
Seventh graders develop strategies for finding the perimeter and area of large geometric figures. Through lecture and guided practice, 7th graders practice the strategy of dividing a geometric shape into smaller more manageable shapes...
Curated OER
Area and Perimeter of Polygons
For 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 Explorer
Students calculate the area of triangles using a variety of materials including computer applets.
Curated OER
Which container holds a larger amount of popcorn?
What does popcorn have to do with math? Seventh grade mathematicians are provided an opportunity to develop a conceptual understanding of the formula for volume and to use it as a tool to solve problems. The lesson begins with a...
Curated OER
Geometry: Area Project
Sixth graders identify and use area formulas for finding the area of geometric shapes.
Curated OER
Geometry of Circles: Week 7
In this circle worksheet, students determine the number of degrees in a minor arc, find the area of a circle, find the area of a shaded region. This two-page worksheet contains six problems.
EngageNY
Modeling Riverbeds with Polynomials (part 1)
Many things in life take the shape of a polynomial curve. Learners design a polynomial function to model a riverbed. Using different strategies, they find the flow rate through the river.