Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, students must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Mathematics Assessment Project
Identifying Similar Triangles
Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...
Curated OER
The Sum of All Angles
Students add up the different angles using the angle addition postulate. In this geometry lesson, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show their...
Curated OER
Rays and Angles
Students view examples of a ray, opposite rays, collinear rays, angles, and straight angles. They discuss and demonstrate how to use a protractor and complete worksheet problems on rays and angles.
EngageNY
Addition and Subtraction Formulas 2
Knowing the addition formulas allows for the calculations of double and half formulas. The fourth installment of 16 has the class use the addition formula to develop the double angle trigonometric formulas. Using the double formula,...
EngageNY
Addition and Subtraction Formulas 1
Show budding mathematicans how to find the sine of pi over 12. The third lesson in a series of 16 introduces the addition and subtraction formulas for trigonometric functions. Class members derive the formulas using the distance formula...
Curated OER
Interior/Exterior Polygon Angles and Tessellations
Students discover the sum of the interior and exterior angles of several polygons. In this Geometers sketchpad lesson, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons. Students...
Curated OER
Does Your Field Measure Up
Learners measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
EngageNY
One-Step Problems in the Real World
Mirror, mirror on the wall, which is the fairest resource of them all? Individuals write and solve one-step equations for problems about angle measurement, including those involving mirrors. Both mathematical and real-world problems are...
EngageNY
Applications of Congruence in Terms of Rigid Motions
Corresponding parts, congruent parts, congruent corresponding parts—what does it all mean? The resource challenges pupils to identify corresponding parts for pairs of figures. It uses examples of figures that undergo rigid...
Curated OER
Determining Angle Measure with Parallel Lines
Students observe and solve examples of corresponding angle postulates, alternate interior angle theorems, and exterior and consecutive angles. They complete the Determining Angle Measure With Parallel Lines worksheet.
Beacon Learning Center
Angles and Algebra
Students calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
Curated OER
How Do You Pay a Complement to an Angle?
Students observe and solve examples of the complementary angle theorem. They complete the How Do You Pay a Complement to an Angle worksheet, and write a response in their math journal.
Curated OER
Vector Lab
Here is a math lab that helps young mathematicians understand the real-life meaning for vector addition. By building a model using spring scales and washers as weight, and then calculating the vector addition using two different methods,...
EngageNY
Unknown Angle Proofs—Writing Proofs
What do Sherlock Holmes and geometry have in common? Why, it is a matter of deductive reasoning as the class learns how to justify each step of a problem. Pupils then present a known fact to ensure that their decision is correct.
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.
Curated OER
Angle Measurement of Aircraft Wings and Tails
Students measure the angles of wings and tails of various aircraft using a protractor. They estimate and check their measurements. They investigate aircraft being developed and tested at NASA Dryden.
Curated OER
Angles and Parallel Lines
Sixth graders draw parallel and intersecting lines to observe and examine the characteristics of alternate interior angles, vertical angles, corresponding angles, and supplementary angles. Through observation, they discover the...
Curated OER
Polygons and Angles
Sixth graders estimate the measurement of angles and then measure the exact distance using an angle ruler. In groups, they explore shapes and recognize the characteristics acute, obtuse and right angles. Students sketch required shapes,...
Ahisma Summer Institute
The Power of One - Math in a Different Angle
In this 2-day lesson focused on exponents, middle schoolers will cross the curriculum by engaging in science, history and language arts activities. Exponential growth will be explored using grains of rice on a chess board. Exponential...
Curated OER
Relationships Among Arc and Angle Measures in Circles
Students follow the directions on the attached worksheet to construct shapes using Geometer's Sketchpad. To start the instructional activity, it is suggested that the teacher guide the students through the initial problem. When...
Curated OER
What's Your Angle
Students create an original lesson about geometry and angles. In small groups they take pictures using a digital camera of obtuse, acute, right, and straight angles that they find at school. Students use the photos in a computer...
Curated OER
Angles and Arcs
Students discuss the sum of central angles and use string to create them on circles. They find the measure and length of both minor and major arcs.
Students give examples of concentric, similar, and congruent circles and congruent arcs.
Alabama Learning Exchange
The Path to Positive
Students demonstrate how to add positive integers. In this computation instructional activity, students read the book Less Than Zero and use a number line and counters to play an addition game using positive integers.