Curated OER
The Sum of All Angles
Young scholars add up the different angles using the angle addition postulate. In this geometry instructional activity, students differentiate between interior and exterior angles. They calculate the different angles for triangles and...
Curated OER
Slope Right Up
Students use triangles to find the length and slope of each side. After connecting the vertices, they add points based on their specific instructions. They use the Pythagorean Theorem to complete a worksheet to end the lesson.
Curated OER
CSI Investigation of Congruence and Similarity
Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
Curated OER
Exploring Trigonometric Ratios
Students identify the ratios of trig functions. In this trigonometry lesson, students construct triangles and use it to derive the values of sine, cosine and tangent. They use Cabri software to create the visual of the identities.
Curated OER
Pythagorean Triple
Learners investigate the properties of the Pythagorean Theorem. In this geometry instructional activity, students identify the missing angles and sides of a right triangle. They label the hypotenuse and legs of a right triangle correctly.
Curated OER
Finding The Area Of Shapes
Fourth graders investigate the concept of computing the area using different shapes. They use prior knowledge in order to devise a formula for a parallelogram. Scaffolding is provided by the teacher to find the formula of area for...
Curated OER
Inscribed Angles
Students calculate the inscribed angle of a triangle. In this geometry lesson, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
Curated OER
Investigating Scale Factors with the Geometer's Sketchpad
Students use Geometer's Sketchpad to examine the scale factor when in is applied to the length of a figure's sides. They look at how the scale factor affects the side lengths, perimeter, and area of the figure that result. They work with...
Curated OER
CSI Investigation
Students solve real life situation using the Pythagorean Theorem. In this geometry lesson, students calculate the length, midpoint and slope of segments. They solve word problems using properties of square roots.
Curated OER
Peter's String
Students are introduced to the math problem and consider how they could approach it. In pairs, students investigate Peter's conjecture in any way they see fit. They then share their answers with the class.
Curated OER
Angles, Parallel Lines, and Polygons
Learners examine how to investigate polygons using an instrument of their own construction. They should be able to prove the general formula for the number of degrees in any polygon (including a triangle). Finally they investigate an...
EngageNY
Tangent Segments
What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
EngageNY
Adding and Subtracting Expressions with Radicals
I can multiply, so why can't I add these radicals? Mathematicians use the distributive property to explain addition of radical expressions. As they learn how to add radicals, they then apply that concept to find the perimeter of polygons.
American Statistical Association
Exploring Geometric Probabilities with Buffon’s Coin Problem
Scholars create and perform experiments attempting to answer Buffon's Coin problem. They discover the relationships between geometry and probability, empirical and theoretical probabilities, and area of a circle and square.
Improving Measurement and Geometry in Elementary Schools
Rep Tiles
In addition to the catchy title, this lesson plan provides upper graders an opportunity to more closely scrutinize the attributes of plane figures. In particular, they focus on the similarity of different shapes. Both whole-class and...
Noyce Foundation
Pizza Crusts
Enough stuffed crust to go around. Pupils calculate the area and perimeter of a variety of pizza shapes, including rectangular and circular. Individuals design rectangular pizzas with a given area to maximize the amount of crust and do...
Futures Channel
Folding Circles
Young scholars investigate properties of circles. For this geometry lesson, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
Curated OER
Property Lists for Quadrilaterals
Students establish classifications of shapes by various properties (angles, sides, etc.). They introduce the important properties of common shapes. Students develop an awareness of the wide variety of ways the 2-D shapes can be alike.
Curated OER
Cabri Jr. Perpendicular Bisector of a Chord
Your learners will construct the perpendicular bisector of a chord. They use Cabri Jr. to construct a circle and a perpendicular bisector of a chord. They then measure lengths of the chords and perpendicular bisectors. Learners use...
Curated OER
Logical Relationship of Postulates & Theorems
In this postulates and theorems learning exercise, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram. They use the concept map to prove theorems...
Curated OER
Geoboard Squares
Students create squares of different sizes on a geoboard. They find and describe a pattern. Students use the pattern to determine the number of squares possible on a 10-by-10 geoboard. They create squares with a horizontal base (and...
Curated OER
Probability and Geometry
Students explore the ways Geometry can help solve probability problems. Students describe platonic solids and practice calculating probability using an online resource. They construct dice with various numbers of sides to demonstrate...
Curated OER
Powerful Polygons
Students scan the classroom to find different common shapes. They listen as the teacher defines polygon and regular polygon. The teacher demonstrates regular polygons via the Internet and the "Math is Fun" web site. Students go outside...