Curated OER
Geometry of Triangles Using a Protractor
Seventh graders use a protractor to measure angles and solve a problem involving distance. In this measuring angles with a protractor lesson plan, 7th graders calculate the distance of a line on a diagram by using a protractor to measure...
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...
Texas Instruments
Exploring Tangents
Explore the concept of tangent lines. In this tangent line lesson, learners graph a circle and two lines on their graphing calculator using Cabri Jr. Students construct the lines so that they both intersect at a given point and are both...
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
Find Someone Who........
Fifth graders identify, describe, and classify lines, line segments, rays, and angles. When given a diagram of a line, they classify the line as perpendicular, parallel, intersecting, vertical, horizontal, and/or diagonal.
Virginia Department of Education
Constructions
Pupils learn the steps for basic constructions using a straightedge, a compass, and a pencil. Pairs develop the skills to copy a segment and an angle, bisect a segment and an angle, and construct parallel and perpendicular lines.
EngageNY
Cyclic Quadrilaterals
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
EngageNY
Special Lines in Triangles (part 1)
Allow your pupils to become the mathematicians! Individuals explore the properties of a midsegment of a triangle through construction and measurement. Once they figure out the properties, learners use them to draw conclusions.
Texas Instruments
Cabri Jr. Inscribed and Central Angles
Learners will differentiate between inscribed and central angles in this geometry lesson. They answer questions dealing with circles as they relate to inscribed triangles and angles. This assignment includes a printable worksheet.
Curated OER
Investigating Segments in a Right Triangle
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...
Curated OER
Basic Geometry Ideas and Angle Measurement
Seventh graders explore the concept of basic geometry. In this basic geometry lesson plan, 7th graders identify the correct picture for a given vocabulary word such as midpoint, line, ray, or parallel lines. Students discuss examples...
Curated OER
Angle Attributes and Measures
Seventh graders explore the concept of angles. In this angles lesson plan, 7th graders use protractors to measure angles. Students sing an angle song. Students discuss attributes of angles using a two-color plate manipulative.
Curated OER
Angles: Angles, Angles, Everywhere
Students estimate and accurately measure the size of angles communicate with the appropriate geometric terms and symbols to describe and name angles, lines, line segments, rays
Curated OER
Lines, Rays, Line Segments, and Planes
Pupils are introduced to lines, rays, line segments and planes and study the differences between them. They also practice graphing lines, rays, line segments and planes
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
EngageNY
Informal Proof of AA Criterion for Similarity
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
EngageNY
Arc Length and Areas of Sectors
How do you find arc lengths and areas of sectors of circles? Young mathematicians investigate the relationship between the radius, central angle, and length of intercepted arc. They then learn how to determine the area of sectors of...
Curated OER
Trigonometric Ratios
Students measure and analyze angles. For this trigonometry lesson, students measure angles and distances use non-traditional techniques. They identify the different ratios of sine, cosine and tangent.
Curated OER
Geometry of Triangles - Week 6
In this geometry of triangles worksheet, learners find the length of sides, are, and angle measurement of inscribed triangles, pentagons, and midpoint of a line. This two-page worksheet contains seven problems.
Curated OER
Classifying and Constructing Corners
Fifth graders, after seeing Honeycomb examples, complete a Classifying Angles worksheet, Clock worksheet, and Defining Angles worksheet.
Curated OER
The Trig to Soccer
Students analyze angles applied to a penalty kick in a soccer game. Based on dimensions of the goal, and the penalty area, students determine where the better chance of scoring lies.
Curated OER
Geometry Journal: Isosceles Triangles
In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
Curated OER
Measuring the Earth
Young scholars identify types of arcs and angles in a circle, find the measure of arcs and angles, and solve real world problems involving lengths of segments in circles, lengths, and areas.