EngageNY
Points of Concurrencies
You say that perpendicular bisectors intersect at a point? I concur! Learners investigate points of concurrencies, specifically, circumcenters and incenters, by constructing perpendicular and angle bisectors of various triangles.
Curated OER
Special Segments in Triangles
Students identify important properties of triangles. In this geometry instructional activity, students differentiate between medians, bisectors and altitudes in a triangle. They identify the properties of these important segments.
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
Congruent Triangles
In this congruent triangles worksheet, 10th graders solve and complete 13 different problems. First, they use the illustrated congruent triangles to show other congruency in each problem. Then, students determine and prove the angle...
Mathematics Vision Project
Geometric Figures
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
Curated OER
Midpoints and Bisectors
In this geometry activity, learners calculate the midpoints of polygons using coordinate pairs. They find the angle bisector, altitude and median of the given triangles. There are 33 questions.
Curated OER
Special Segments in a Triangle
For this geometry worksheet, 10th graders review the vocabulary associated with the special segments of a triangle and the associated points of concurrency and solve problems in which they find the indicated missing angle or segment. ...
Curated OER
Congruent Triangles
In this congruent triangles worksheet, 10th graders solve and complete 16 different types of problems. First, they name the corresponding parts of the congruent triangles shown and draw a picture. Then, students list the five ways to...
Curated OER
Isosceles Triangles
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
Curated OER
Studying Special Segments in Triangles
Learners investigate special segments in triangles. In this geometry lesson, students graph, compare, estimate and predict findings based on their data. They differentiate between similarity and congruence of triangles.
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
Special Triangles and Circles
Students investigate special triangles and circles. In this geometry instructional activity, students construct a perpendicular bisector and discuss angles of a triangle. They find the angle bisectors, vetex and the types of circle...
Curated OER
Hospital Locator
Pupils apply properties of triangles to the real world. In this geometry lesson, students identify the median and angle bisectors of triangles. They plan the appropriate are to place a new medical center based on their knowledge of...
Curated OER
Incenter of a Triangle
Tenth graders find the incenter of a triangle. For this geometry lesson, 10th graders define the way to create an incenter with an angle bisector. They differentiate between incenter and incircle.
Curated OER
Investigating Trigonometric Ratios Through Similar Right Triangles
Students identify similar and congruent right triangles. For this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.
Mathematics Vision Project
Module 3: Geometric Figures
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
Curated OER
IGD: Perpendicular Bisector
Students draw perpendicular bisectors. In this perpendicular bisectors lesson, students identify the perpendicular bisector in a polygon. They use web tools to create and measure perpendicular bisectors. Students identify lines of...
Curated OER
Pedal Triangles
Students identify the properties and theorems of triangles. In this geometry lesson plan, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
Curated OER
Special Segments is a Triangle
In this geometry worksheet, 10th graders examine the special segments that occur in a triangle. The three page worksheet contains twenty-five problems. Answers are not included.
Curated OER
Triangles
In this triangles worksheet, 10th graders solve and complete 6 various types of problems. First, they draw a median and the altitude from the given angle in each triangle illustrated. Then, students determine which angle is equidistant...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Curated OER
Constructions of Isosceles and Equilateral Triangles
Pupils explore the difference between drawing and constructing a triangle utilizing The Geometer's Sketchpad on the computer. They create, develop and script constructions for both isosceles and equilateral triangles. Each student has to...
Curated OER
Ruler and Compass Constructions
Fourth and fifth graders examine how to construct perpendicular lines and to bisect angles using rulers and compasses in this unit of lessons. They design a number of polygons using these methods.
Curated OER
Exploring Special Segments in Triangles
Young scholars discover that four special segments have a common intersection point. They identify the position of the intersection point in triangles. They produce conjectures about areas of the divided triangles.