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
Sequencing Rotations
Discover the result of a sequence of rotations about different centers. Pupils perform rotations to examine the patterns. They also describe the sequence of rotations that performed to reach a desired result in the ninth installment in a...
Radford University
Developing a Trigonometry Phone App
What's one more app? After reviewing how to calculate missing side lengths or angle measures in a right triangle, pupils create instructions for a phone app to do all of the tedious work. They must consider all nine cases of known...
Curated OER
Worksheet 7: Slope and Tangents
Providing both review and practice problems, this worksheet prompts students to answer five questions having to do with slope, tangents lines, graphing, the Squeeze Theorem, differentiable functions and derivatives. This activity could...
Curated OER
Student Reading - The Unique Properties of Water
Without water there would be no life on this planet. Biology learners find out why by reading this handout. Create a worksheet of questions to answer after the reading. Follow it up with quick demonstrations or laboratory activities that...
Curated OER
Archimedes
For this Archimedes worksheet, students complete and respond to 4 different problems related to different triangles. First, they find the midpoint of each side of a given triangle. Then, students connect the midpoints with the opposite...
Curated OER
Group Isomorphisms
Students identify and apply properties of triangles. In this geometry lesson, students define equilateral triangles by sides and angles. They build cardboard triangles as they study properties of triangles.
Curated OER
Exploring Polygons and The Greedy Triangle
Excellent lesson plan! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump ropes),...
Curated OER
Tessellation Trial and Error
In this interactive lesson, students review attributes of equilateral polygons. They are introduced to the concept of a tessellation. Using protractors and pre-cut shapes, students arrange a variety of tiles to create tessellations. They...
Curated OER
Bisectors of Triangles
In this geometry worksheet, 10th graders solve problems involving the perpendicular bisectors and angle bisectors of a triangle and their points of concurrency. The one page worksheet contains sixteen questions. Answers...
Key Curriculum Press
Triangle Inequalities
Properties about triangles are explored in this lesson. Geometers make conjectures about the length of a triangle's sides, the length of the angles in relation to the length of the sides, and the measure of the exterior angles of a...
Curated OER
PRE ALGEBRA
Eighth graders find missing angles of triangles, quadrilaterals and angles formed by parallel lines cut by a transversal. They use area formulas to find the area of a figure; find the complement and supplement of a given angle; and know...
Curated OER
Triangle worksheets
In this geometry worksheet, 10th graders explore triangle properties, including the sum of the measures of the angles of a triangle, the triangle inequalities, properties of isosceles triangles, properties of congruent triangles, and...
Curated OER
Reflections Of
Students create angles using mirrors. In this angle reflection lesson, students draw angles, then use mirrors to create angles using reflections and measure the new angles.
EngageNY
The Side-Angle-Side (SAS) and Side-Side-Side (SSS) Criteria for Two Triangles to Be Similar
Playing with mathematics can invoke curiosity and excitement. As pupils construct triangles with given criteria, they determine the necessary requirements to support similarity. After determining the criteria, they practice...
National Security Agency
Classifying Triangles
Building on young mathematicians' prior knowledge of three-sided shapes, this lesson series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...
EngageNY
Triangle Congruency Proofs (part 1)
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
Curated OER
Geometry - Angles Overview
Learners address 14 questions that include naming all pairs of opposite and supplementary angles for sets of intersecting lines and then, finding the measure of the unknown angle. They determine the measure of the angle that is...
EngageNY
Ptolemy's Theorem
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Curated OER
Triangles
In this triangles instructional activity, 10th graders solve 3 extensive informal geometry problems that involve triangles. First, they sketch a triangle, selecting 3 of the sides and constructing 3 midpoints. Students then draw each of...
Curated OER
SSS, SAS, ASA, and AAS Congruence
Students will determine if triangles are congruent and state the appropriate congruence theorem. In this geometry lesson, students will determine what information is needed to determine if a pair of triangles are congruent using ASA,...
Curated OER
Logical Relationship of Postulates & Theorems
For this postulates and theorems worksheet, 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
Section 6.1-6.2 Precalculus: Trigonometry
In this trigonometry worksheet, learners solve 15 triangle problems. Students use the law of sines and law of cosines to find the missing angles and side lengths of a triangles.
Math Mammoth
Construct Line Segments and Angles
In this math activity, learners are asked to used a compass and straight edge to construct copies of shapes, angles and line segments.