Worksheet
Curated OER

Finding Area of Triangles

For Students 5th - 6th
In this area of triangles instructional activity, students calculate the area of 4 given triangles, writing total area beneath each. A reference web site is given for additional activities. 
Worksheet
Curated OER

Area of Triangles

For Students 6th - 8th
In this math learning exercise, students draw two triangles and one pentagon. Then they use the correct formula to calculate the area for each.
Lesson Plan
Curated OER

Area Measures and Right Triangles

For Teachers 9th - 12th Standards
Your class will investigate the relationship among different triangles. This geometry lesson, demonstrates how to make a connection between triangles and the Pythagorean Theorem. They identify the missing side or angle of a triangle.
Lesson Plan
Curated OER

Exploring the Circumcenter of a Triangle

For Teachers 9th - 12th Standards
Students construct the circumcenter of a triangle. For 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...
Lesson Plan
Curated OER

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 activity provides an...
Lesson Plan
Curated OER

Triangle Midsegment

For Teachers 9th - 12th Standards
Learn how to calculate the length and midsegments of triangles. Students differentiate between similar and congruent triangles. They create a spreadsheet with their findings.
Lesson Plan
Curated OER

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
Curated OER

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
Curated OER

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...
Lesson Plan
Curated OER

Nested Similar Triangles

For Teachers 9th - 12th Standards
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...
Lesson Plan
Curated OER

Midsegments of a Triangle

For Teachers 9th - 12th Standards
Students 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...
Lesson Plan
Curated OER

Triangle Sum Theorem

For Teachers 9th - 12th Standards
Teach your class how to solve problems using the triangle sum theorem. In this geometry instructional activity, students identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the sides...
Lesson Plan
Curated OER

30-60-90 Right Triangles in Cabri Jr.

For Teachers 9th - 12th Standards
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...
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

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...
Worksheet
Curated OER

Calculating in Construction - Area

For Students 8th - 12th
In this area worksheet, learners solve 6 short answer problems. Students find the area of a figure composed of regular polygons such as triangles, rectangles, squares, etc given a sketch of the figure.
Assessment
Inside Mathematics

Patterns in Prague

For Teachers 8th Standards
Designers in Prague are not diagonally challenged. The mini-assessment provides a complex pattern made from blocks. Individuals use the pattern to find the area and perimeter of the design. To find the perimeter, they use the Pythagorean...
Assessment
Concord Consortium

Divisions

For Students 7th - 12th Standards
Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.
Worksheet
Curated OER

Area and Perimeter

For Students 10th
In this area and perimeter worksheet, 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 perimeter of...
Lesson Plan
Curated OER

Flip's Flag

For Teachers 5th
Fifth graders apply the symmetry and angle properties of polygons and use fractions to express the relationships between the areas of rectangles, squares, and triangles. They analyze various country flags and develop mathematical...
Worksheet
Curated OER

Area of Triangles

For Students 10th
In this geometry worksheet, 10th graders calculate the area of right triangles using the Pythagorean Theorem combined with the area formula. There are 14 questions with an answer key.
Lesson Plan
Curated OER

Areas of Trapezoids, Rhombuses and Kites

For Teachers 8th - 10th
Students calculate the area of different polygons. In this geometry lesson, students find the area for trapezoids, rhombuses and kites.
Lesson Plan
Curated OER

Does the Area of the Quadrilateral Change?

For Teachers 5th - 6th
Students study area and quadrilaterals. In this multiplication and area lesson, students use Polystrip models to change rectangles to form different parallelograms. Students find the area of the models use a Geometer Sketchpad to find...
Worksheet
Curated OER

Perimeter and Area

For Students 4th - 6th
For this perimeter and area worksheet, students find area and perimeter for a set of 9 triangles. A website reference is given for additional resources.