Curated OER
Obtuse Triangles
Fourth graders explore obtuse triangles. For this geometry lesson, 4th graders make obtuse triangles with paper and scissors. They determine how to find the center of their triangle.
Curated OER
Geometry Worksheet: Pythagoras' Theorem
In this Pythagorean Theorem worksheet, students use the Pythagorean Theorem to find the length of the unlabeled side of the right triangle. There are 8 problems all together.
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.
Curated OER
Geometry
Students are introduced to the basics of Geometry. Using cutout shapes, they identify whether they are polygons by using the properties of polygons. They practice drawing shapes they are going to be using on an everyday basis and...
Futures Channel
Folding Circles
Students investigate properties of circles. In this geometry lesson, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
Curated OER
Fractals Teachers' Notes
When you see a flower or a tree in nature do you see the math? This web resource contains many ideas for using fractals in a math class including Sierpinski’s triangle, Koch's Snowflake, and the Jurassic Park Fractal. Additionally, it...
Willow Tree
Area of Common Geometric Figures
Scholars can use area formulas, but can they apply what they know about area? The activity challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
Curated OER
Can a Geometric Mean be Nice?
In this Geometry instructional (work)sheet, young scholars are instructed on how to find the geometric mean. Students are then shown how the geometric mean is applied to proving similar triangles.
Curated OER
Triangles with Collinear Circumcenters
Students identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.
Curated OER
Constructing Midsegments of Triangles
Learners construct midsegments. In this geometry lesson plan, students make conjectures and apply properties of triangles to solve problems. They complete an activity on the computer.
Illustrative Mathematics
Reflections and Isosceles Triangles
Geometers explore symmetries of isosceles triangles by using rigid transformations of the plane. They complete four tasks, including congruence proofs, which illustrate the relationship between congruence and rigid transformations. The...
Curated OER
Transformational Geometry Using the Geometer's Sketchpad
Students complete a webquest on the various types of symmetry. Using a computer, they explore the concepts of transformational geometry and identify points, segments, lines and planes. They experiment with the rotation of a quadrilateral...
EngageNY
General Pyramids and Cones and Their Cross-Sections
Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...
CK-12 Foundation
Ambiguous Case: Furniture Store Problems
Remove any ambiguity about using a helpful resource. Individuals use an interactive to find the number of triangles that fit given conditions. They find that some conditions can result in more than one triangle in the ambiguous case.
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
CK-12 Foundation
Pythagorean Theorem and Its Converse
To be a right triangle, or not to be — that is the question. Scholars drag line segments in an Internet application to see if they form right triangles. Once they get the results of the activity, they connect them to the converse of the...
CK-12 Foundation
Unit Circle: Medieval Castle Defense
Who needs a plan — let trigonometry protect you! Pupils determine the angle of an approaching enemy to a village wall. The scholars determine the exact value of trigonometric functions for the angle. Class members use trigonometry to...
Curated OER
Altitudes and Orthocenters: Making Connections to the Nine-Point Circle
Young scholars practice various equations for constructing nine-point circles for triangles.
Curated OER
Investigating Trigonometric Ratios Through Similar Right Triangles.
49Learners investigate the properties of right triangles. In this geometry activity, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
Curated OER
Investigating the Sierpinski Triangle
Students solve and analyze the sierpinski's triangle. In this geometry lesson, students identify properties and theorem of triangles. They solve problems involving angles and sides of triangles.
Curated OER
Why can't We Use SSA to Prove Triangles Congruent?
Students investigate triangles and congruences. In this geometry lesson plan, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.
Curated OER
Altitude Locator
Pupils use protractors, strings, and straws to construct a device used to determine the height of tall objects. In this applied geometry lesson, students use common objects to construct a tangent height guide. They use principles of...
Curated OER
Pedal Triangles
Students identify the properties and theorems of triangles. In this geometry lesson, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
Curated OER
The Minimal Distance Point from the Vertices of a Triangle
Young scholars calculate the distance from the vertex of a triangle to the center. In this geometry lesson, students find the shortest distance between a point and the vertex of a triangle. They relate this concept of distance to the...