Lesson Plan
Illustrative Mathematics

Joining Two Midpoints of Sides of a Triangle

For Teachers 9th - 11th Standards
Without ever using the actual term, this exercise has the learner develop the key properties of the midsegment of a triangle. This task leads the class to discover a proof of similar triangles using the properties of parallel...
Lesson Plan
Curated OER

Triangle's Interior Angles

For Teachers 7th - 9th Standards
Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.
Activity
Illustrative Mathematics

Is This a Parallelogram?

For Teachers 9th - 12th Standards
If both pairs of opposite sides of a quadrilateral are congruent, is the quadrilateral a parallelogram? This task asks learners to determine the answer and to support their answer with a proof. The resource includes a commentary for...
Activity
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Illustrative Mathematics

Midpoints of the Sides of a Paralellogram

For Teachers 9th - 12th Standards
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Activity
Education Development Center

Proof with Parallelogram Vertices

For Teachers 8th - 10th Standards
Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.
Activity
Texas Instruments

Texas Instruments: Angles Formed by Parallel Lines and a Transversal

For Teachers 9th - 10th Standards
Students explore relationships in various angles formed by 2 parallel lines and a transversal.
Activity
Texas Instruments

Texas Instruments: Parallel Lines, Transversals and Angles

For Teachers 6th - 8th Standards
This activity allows students to: 1. Identify the pairs of angles formed when a transversal intersects two lines.: 2. Measure angles Using Cabri Jr. 3. Identify relationships between pairs of angles when a transversal intersects parallel...
Activity
Texas Instruments

Texas Instruments: Parallel Lines Cut by a Transversal With Cabri Jr.

For Teachers 9th - 10th
Using Cabri Jr, the students (with the teachers help) will create parallel lines cut by a transversal, measure angles, and compare the relationships of the angles formed using features of the Cabri Jr.
Activity
Texas Instruments

Texas Instruments: Properties of Parallel Lines Cut by a Transversal

For Teachers 9th - 10th
In this activity, students create parallel lines and a transversal, and study the properties of the lines and their angles.
Activity
Texas Instruments

Texas Instruments: Parallel Lines Cut by a Transversal

For Teachers 9th - 10th
In this activity, students learn and increase their knowledge about the angles formed when parallel lines are cut by a transversal.
Activity
Texas Instruments

Texas Instruments: Angles Formed by Parallel Lines

For Teachers 9th - 10th Standards
Students can use Cabri Jr. to construct parallel lines and transversals. They will make conjectures about the angles that are formed.
Activity
Texas Instruments

Texas Instruments: Sail Problem (Parallel Lines & Segment Relationships)

For Teachers 9th - 10th
In this activity, students will explore the proportional relationships involved in multiple parallel lines being cut by transversals. These relationships are approached through exploration of a sail design problem, where students are to...
Activity
Texas Instruments

Texas Instruments: Angles and Transversals

For Teachers 9th - 10th
Students explore the relationships of angles formed when two parallel or non-parallel lines are cut by a transversal. This activity investigates the terms: Transversal, corresponding angles, alternate interior angles, alternate exterior...
Activity
Analyze Math

Analyze Math: Parallel Lines and Angles Problems

For Students 9th - 10th
Try these three problems about finding the measures of different angles that arise from diagrams involving parallel lines and transversals. Detailed solutions are written out for these three problems of moderate difficulty.
Activity
Varsity Tutors

Varsity Tutors: Hotmath: Graphing Calculator: Parallel, Perpendicular, Slope, Transversal

For Students 9th - 10th Standards
Practice using your graphing calculator for drawing parallel lines, perpendicular lines, slope, and transversals. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly...
Activity
CK-12 Foundation

Ck 12: Parallel Lines and Transversals

For Students 9th - 10th
[Free Registration/Login Required] Students will answer real world problems by determing where to add the additional beam using parallel lines and transversals. Click learn more to watch a video and click challenge me to answer a...
Activity
Texas Instruments

Texas Instruments: Parallel Lines

For Teachers 9th - 10th
This file contains questions related to parallel lines cut by a transversal and the angles formed. The questions can be used to asses your students' understanding of this topic in geometry.
Activity
Varsity Tutors

Varsity Tutors: Hotmath: Slope, Parallel & Perpendicular Lines & Transversals

For Students 9th - 10th Standards
Twenty-five problems cover the topics of slope, parallel lines, perpendicular lines, and transversals in different settings. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the...