+
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

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...
+
Worksheet
Curated OER

Triangle Pennies

For Students 10th
For this geometry worksheet, 10th graders arrange pennies in the form of a triangle. They then remove three pennies to rearrange the shape of the triangle and diagram it. An answer key is provided.
+
Worksheet
Curated OER

Area of 2D Shapes Homework

For Students 9th - 12th
In this geometry worksheet, students solve the area of 2D shapes starting with squares, rectangles, parallelograms, triangles, rhombi, trapezoids, circles, and ending with area of shaded regions. There are 20 questions.
+
Handout
El Paso Community College

Geometry Definitions

For Students 7th - 9th Standards
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 
+
Worksheet
Curated OER

Geometry Level 3

For Students 7th - 9th Standards
What a wonderful resource! Learners create two-dimensional shapes according to the instructions stated, use the squares to make a triangular prism, a cube, and a pyramid, and identify features of plane shapes, among a myriad of other...
+
Interactive
CK-12 Foundation

Identify Accurate Drawings of Triangles: Law of Cosines

For Students 10th - 12th Standards
Drawing triangles is easy, even if you have to calculate the exact length of its sides. Scholars use the Law of Cosines to find missing sides of triangles. An interactive helps them check their answers.
+
Lesson Plan
Curated OER

Exploring Geometric Figures

For Teachers 10th
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain an...
+
Lesson Plan
Curated OER

Does Your Field Measure Up

For Teachers 9th - 11th
Students measure angles using a plane table kit. In this geometry instructional activity, students use trigonometric identities to find the values of the length of a football field.
+
Worksheet
Curated OER

Transformations and Translations in Geometry

For Students 8th - 10th Standards
In this transformations and translations in Geometry worksheet, learners use geometric shapes and grids to translate six transformations in each of two activities.
+
Interactive
CK-12 Foundation

Polygon Classification

For Students 8th - 10th
Polly want a polygon? Young mathematicians sort shapes using an interactive. They classify the shapes as convex polygons, concave polygons, or not polygons.
+
Worksheet
Curated OER

Symmetry Using Polygons

For Students 8th - 10th
Working on symmetry in your class? If so, this learning exercise might be for you. Learners observe different triangles and quadrilaterals, determine which are symmetrical, draw in the lines of symmetry, and color the symmetrical shapes....
+
Assessment
Concord Consortium

Three Rubber Bands

For Students 7th - 12th Standards
Stretch your mind about triangles. Given a triangle, scholars consider a smaller triangle formed when they stretch three rubber bands from each vertex to the opposite side. They determine the ratios of the areas and perimeters of the...
+
Worksheet
Curated OER

Quiz: Areas and Coordinate Geometry

For Students 8th - Higher Ed
For this area worksheet, students find the area of ten figures that are drawn on a coordinate grid. Five of the shapes are triangles. Five shapes are irregular quadrilaterals.
+
Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve 10 different problems that include determining the measurement of various angles. First, they determine the area of a triangle illustrated on the sheet. Then, students use the picture to...
+
Lesson Plan
Curated OER

Triangle Congruence

For Teachers 9th - 11th
Learners use web applet to create congruent triangles. For this geometry lesson, students differentiate between congruent and similar. They create shapes online and drag those shapes around to create visuals of triangles.
+
Lesson Plan
Curated OER

Investigating Lengths of Segments in a Triangle

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

Exploring the Centroid of a Triangle

For Teachers 9th - 12th Standards
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...
+
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.
+
Lesson Plan
1
1
Illustrative Mathematics

Why Does SSS Work?

For Teachers 9th - 10th Standards
While it may seem incredibly obvious to the geometry student that congruent sides make congruent triangles, the proving of this by definition actually takes a bit of work. This exercise steps the class through this kind of proof by...
+
Lesson Plan
Willow Tree

Perimeter of Common Geometric Figures

For Students 8th - 11th Standards
Help learners understand that perimeter and circumference are one in the same. Learners apply their skills to determine the perimeter/circumference of triangles, rectangles, and circles. They then use the same strategy to find the...
+
Lesson Plan
Curated OER

Identify triangles

For Teachers 9th - 10th
Students explore triangles. In this geometry instructional activity, students will create note cards with pictorial depictions of right, acute,obtuse, scalene, isosceles, equilateral and equiangular triangles. Students will verbally...
+
Worksheet
Curated OER

Geometry Worksheet #13

For Students 10th
In this geometry worksheet #13 worksheet, 10th graders work in groups to solve 6 geometry problems, involving measurement of angles.