Curated OER
Introduction to Parallel Lines in Euclidean Space and in Spherical Space
Eighth graders are introduced to the basic concepts of Geometry and their definitions in Euclidean space. They draw and define the following terms: point, line, and line segment. Students also define the terms colliner and...
EngageNY
Problem Solving and the Coordinate Plane
Class members investigate rectangles on the coordinate plane. They determine the length of line segments in the coordinate plane with the same x-coordinate or same y-coordinate and then solve geometric problems involving perimeter...
Curated OER
Perpendicular Bisector of a Line Segment
High Schoolers investigate the perpendicular bisector of a line segment. They use Cabri Jr. to construct the perpendicular bisector of a segment. The dynamics capabilities of Cabri Jr. allow your learners to observe the lengths of the...
EngageNY
Families of Parallel Lines and the Circumference of the Earth
How do you fit a tape measure around the Earth? No need if you know a little geometry! Pupils begin by extending their understanding of the Side Splitter Theorem to a transversal cut by parallel lines. Once they identify the...
EngageNY
How Do Dilations Map Segments?
Do you view proofs as an essential geometric skill? The resource builds on an understanding of dilations by proving the Dilation Theorem of Segments. Pupils learn to question and verify rather than make assumptions.
Virginia Department of Education
Arc Length and Area of a Sector
What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...
Curated OER
Segment and Distance
Students explore the definitions of segment and distance. They perform hands-on activities to form a segment and examine distance. Following teacher guidance, they construct congruent line segments. Independently, they find the...
Curated OER
Midpoint of a Segment
Learners revisit midpoint and segments by graphing on the TI or computer. This activity can be done with pencil and paper, but is more interactive if it is done on a TI-navigator.
EngageNY
First Consequences of FTS
Challenge the young mathematicians to find the exact coordinates of a dilated point. The fifth segment in a 16-part series introduces the class to the converse of the Fundamental Theorem of Similarity. Scholars use the theorem to...
EngageNY
Distance on the Coordinate Plane
Scholars learn how to find the distance of vertical and horizontal line segments on the coordinate plane in the 19th installment of a 21-part module. The use of absolute value comes in handy.
Curated OER
Investigating Segments in a Triangle
Pupils investigate segments in a triangle by constructing a triangle using Cabri Jr. They construct segments within the triangle that lie on the midpoints of the triangle's sides. Learners then compare the slope of base of the triangle...
Texas Instruments
Investigating Segments in a Quadrilateral
Investigate the properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral. For this properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral lesson, learners...
Curated OER
Measuring Angles & Segments
Students view a PowerPoint for a warm-up lesson. They practice measuring around the classroom, measuring such things as the length and width of a desk, pencil, door, and book. Students use a website to practice measuring angles.
EngageNY
The Distance from a Point to a Line
What is the fastest way to get from point A to line l? A straight perpendicular line! Learners use what they have learned in the previous lessons in this series and develop a formula for finding the shortest distance from...
Curated OER
Measurement 4: Linear Measure
In this measurement worksheet, students use a ruler to measure, in inches, the distance of various line segments. Then, using the scale drawing, they determine the actual distance in miles. Students may use their knowledge of proportions...
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...
Virginia Department of Education
Side to Side
Congruent figures: two figures that want to be just like each other. Individuals learn to distinguish between figures that are congruent and those that are not. Measuring the lengths of line segments and angles helps in this endeavor.
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
Rational Numbers on the Number Line
Individuals learn how to plot rational numbers on the number line in the sixth lesson of a 21-part module. They identify appropriate units and determine opposites of rational numbers.
Curated OER
Geometry: Lesson 1: Points, Lines, Segments, Angles
Fourth graders examine the concepts of, draw, and label points, lines, segments, and angles, They draw, label, and identify horizontal, vertical, intersecting, parallel, and perpendicular lines. They complete an associated worksheet that...
EngageNY
Special Lines in Triangles (part 2)
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
EngageNY
Fundamental Theorem of Similarity (FTS)
How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line...
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.
Curated OER
Points, Lines, and Distance
Learners calculate the distance between two points. In this geometry lesson plan, students define the meaning of the distance between parallel lines. They find the point of intersection of other lines.