Lesson Plan
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Circumscribing a Circle About a Triangle

For Teachers 9th - 12th Standards
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...
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Exploring the Circumcenter of a Triangle

For Teachers 9th - 12th Standards
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...
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Investigating Area Relationships

For Teachers 9th - 12th Standards
Learners investigate the area of various figures. They construct triangles and quadrilaterals using Cabri Jr. and discuss the relationships between different angles, side lengths, and figures.
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Investigating Segments in a Triangle

For Teachers 9th - 12th Standards
Pupils investigate segments in a triangle by constructing a triangle using Cabri Jr. They construct segments within the triangle that lie on the midpoints of the triangle's sides. Learners then compare the slope of base of the triangle...
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Investigating Segments in a Right Triangle

For Teachers 9th - 12th Standards
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...
Lesson Plan
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Congruent Triangles

For Teachers 9th - 12th
Students explore the concept of congruent triangles.  In this congruent triangles lesson, students use Cabri Jr. to construct two congruent triangles using circles.  Students determine if the two triangles are congruent by...
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Measuring Angles in a Triangle

For Teachers 9th - 12th Standards
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...
Lesson Plan
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Perpendicular Bisector Theorem

For Teachers 9th - 12th Standards
High schoolers construct perpendicular bisectors using Cabri Jr. on their graphing calculator. They then construct conditional statements about perpendicular bisectors along with their converse, inverse, and contrapositive.
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Exploring the Orthocenter of a Triangle

For Teachers 9th - 12th Standards
Young mathematicians explore the concept of triangles as they construct altitudes of triangles to find the orthocenter. Learners construct their triangles using Cabri Jr. on their graphing calculators and find that the altitudes of a...
Lesson Plan
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Constructions Triangles

For Teachers 10th Standards
Learners explore the difference between a construction and a drawing. They focus on various ways to construct different types of triangles. The activity is an application of Cabri Jr. and reinforces the difference between a constructions...
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Triangle Inequality Theorem

For Teachers 9th - 12th Standards
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...
Lesson Plan
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Midsegments of Quadrilaterals

For Teachers 9th - 12th Standards
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.
Lesson Plan
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Midsegments of a Triangle

For Teachers 9th - 12th Standards
High schoolers analyze midsegments of triangles in this instructional activity. They use Cabri Jr. software to observe the relationships between interior angles and midsegments of triangles. Specific instructions for creating this...
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Ratios in Right Triangles

For Teachers 9th - 12th Standards
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...
Lesson Plan
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Triangles: Triangle Inequalities

For Teachers 9th - 12th Standards
Using SketchPad on their calculators to construct triangles, students measure exterior angles and remote interior angles of their constructed triangle. Students develop the triangle inequality from observation and exploration with their...
Lesson Plan
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Introductory Lesson- Patterns

For Teachers 1st
First graders explore patterns in mathematical context. In this patterns lesson, 1st graders inspect patterns shown to them, copy patterns, complete patterns and create patterns of their own. These patterns are shown by actions, drawing,...
Lesson Plan
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How many isosceles Triangles Can You Find?

For Teachers 5th
Fifth graders solve problems while examining a variety of isosceles triangles.  In this isosceles triangle lesson plan, 5th graders examine shapes to find their characteristics.  Students pay particular attention to the...
Lesson Plan
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How many isosceles triangles can you find?

For Teachers 7th
Seventh graders recognize the characteristics of isosceles triangles. In this isosceles triangle lesson, 7th graders use geoboards to create isosceles triangles. Students record results and explain why they have an isosceles triangle.
Worksheet
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Addition of Shapes

For Students 1st - 2nd
For this addition worksheet, students count, write and add together 6 sets of different color-coded shapes in the boxes provided. Students totals will average between 10 and 18.
Lesson Plan
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Shapes and Introduction to Geometry

For Teachers 2nd - 4th
Students make a quilt. In this geometry instructional activity, students discuss patchwork quilts and learn some different geometric shapes and patterns that are commonly used. Students explore designs with triangles and squares and then...
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Angles, Triangles, Quadrilaterals, Circles and Related

For Teachers 6th - 8th
Students classify angles. In this angles activity, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a...
Worksheet
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Learning Triangles

For Students K - 1st
In this triangles worksheet, students recognize triangles. Students complete the worksheet by practicing drawing triangles and recognizing triangles in a picture.
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Surface Area of Prisms

For Teachers 8th - 10th
Young scholars compute surface area and volume of prisms. In this surface area lesson, students find the surface area and volume of rectangular and triangular prisms. Independently, young scholars use their computers to determine the...
Worksheet
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Finding Trigonometric Ratios

For Students 11th
In this finding trigonometric ratios worksheet, 11th graders solve and complete 22 various types of problems. First, they find the value of each trigonometric ratio to the nearest ten-thousandth. Then, students use a calculator to find...