Curated OER
Intersecting Lines and Vertical Angles
Pupils identify and define intersecting lines and vertical angles. They draw two intersecting lines and measure one pair of vertical angles. Learners will also move a line to change the angles of a figure and describe the changes in the...
EngageNY
Solve for Unknown Angles—Angles and Lines at a Point
How do you solve for an unknown angle? For this sixth installment of a 36-part series, young mathematicians use concepts learned in middle school geometry to set up and solve linear equations to find angle measures.
Virginia Department of Education
Lines and Angles
Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history activity with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete practice...
Virginia Department of Education
Middle School Mathematics Vocabulary Word Wall Cards
Having a good working knowledge of math vocabulary is so important for learners as they progress through different levels of mathematical learning. Here is 125 pages worth of wonderfully constructed vocabulary and concept review cards....
Illustrative Mathematics
Find the Missing Angle
This one activity requires young geometers to pull together information they are currently learning with things they have learned previously. Here they rely on understanding something about parallel lines, alternative interior angles,...
EngageNY
Unknown Angles
How do you solve an equation like trigonometry? Learners apply their understanding of trigonometric ratios to find unknown angles in right triangles. They learn the meaning of arcsine, arccosine, and arctangent. Problems include basic...
Curated OER
Does Your Field Measure Up
Students measure angles using a plane table kit. In this geometry instructional activity, students use trigonometric identities to find the values of the length of a football field.
Curated OER
Measuring the Earth
High schoolers use principles of geometry to measure the circumference of the Earth. In this applied geometry lesson plan, students use mathematics to determine scientific information. They make measurements, calculate the central angle,...
Curated OER
Positive and Negative Angles and Arcs
To better understand that the intersection point of two lines lies inside a circle, learners use their keen measurement skills. They discuss arcs, rays, tangent lines, and reflex angles. Then, they put their skills to work as they...
Geometry Accelerated
Accelerated Geometry Review Sheet
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
Curated OER
Angle Pairs
High schoolers practice identifying right, vertical, and adjacent angles using a Smartboard. They then determine measurements of all of the angles when only one measurement is given.
Curated OER
Vectors
Represent motion with arrows and call them vectors! The lesson is a presentation that models the mathematics involved when determining a resultant vector. It addrssses motions that are parallel, perpendicular, and a combination of both.
Curated OER
Triangles Inscribed in a Circle
Are you tired of answers without understanding? Learners can give a correct response, but do they really understand the concept? Have young mathematicians think deeper about linear functions, angles, and formulas in algebra. Learners are...
EngageNY
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
Curated OER
Angles and Parallel Lines
In this geometry activity, students identify the different angles formed by cut parallel lines. They name the angles and find the measures of each. There are 24 questions.
Curated OER
Task: Miniature Golf
"Fore!" All right, no one really yells this out in miniature golf, but this well-defined activity will have your charges using lots of numbers in their unique design of a miniature golf hole. Included in the activity criteria is the...
EngageNY
Secant Lines; Secant Lines That Meet Inside a Circle
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Curated OER
Unit Squares and Triangles
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle and angle...
Illustrative Mathematics
Paper Clip
With minimal setup and maximum freedom, young geometers are encouraged to think outside the box on a seemingly simple application problem. Though the task seems simple, measuring a given paper clip and finding how many 10 meters can...
Curated OER
Talking About Your Name in Math Terms
Add imagination and creativity to your math lesson plan. Young mathematicians investigate ways to express their names in mathematical terms. For instance, they can count the number of letters, analyze the geometric shapes of the letters,...
Curated OER
Square Graphs
Learners identify the different properties of quadrilaterals. In this geometry-lesson, students define parallel sides and diagonals of polygons as they compare to a quadrilateral. They identify the methods to find the angles in a...
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
Points, Lines, Planes, and Space
In this points, lines, planes, and space worksheet, young scholars solve word problems dealing with points, lines, planes, and space. Students complete 20 individual problems and 20 group problems.