Once you start looking, angles appear everywhere in our daily lives. A creative lesson has learners use the angles created by a fuel gauge to practice the Angle Addition Postulate. They see how changing the angle parts does not...

Fourth and fifth graders investigate angles and name them according to the criteria for obtuse, acute, and right angles. They examine a human-made yarn pattern on the floor of their classroom and identify angles, vertices, and types of...

Build angles from angles. Using the Angle Addition Postulate, learners find the measures of unknown angles. The interactive simulation shows a visual representation of the postulate and allows individuals to manipulate the angles and...

Fourth and fifth graders make a protractor and identify various angle types. In this protractor and angle lesson, learners make their own protractor and use it to measure a variety of angles. They complete worksheets while identifying...

Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The lesson emphasizes the vocabulary related to these...

Students identify and create angles. In this angle measurement lesson, students use sticks to make models of angles, then measure and name each angle.

Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...

Inscribed angles are central to the lesson plan. Young mathematicians build upon concepts learned in the previous lesson plan and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson plan then guides...

Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...

Middle schoolers explore angle measure as they estimate angle measure and measure and draw angles of less than 360 degrees. The lesson emphasizes the use of estimation when measuring angles.

Students 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.

Student complete worksheet using the definitions of lines and angle vocabulary. They define the word and follow a direction given on the worksheet such "construct a line." They complete an online tutorial on how to measure angles using a...

Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...

Explore angle relationships created by parallel lines and transversals. The 13th lesson of 18 prompts scholars use transparency paper to discover angle relationships related to transversals. Learners find out that these angles pairs are...

Acute or obtuse? Seems right to me! As scholars explore the simulation, they investigate angle measures. Questions ask them to classify the angles using correct naming conventions.

It's all about the patterns! Young scholars learn that the unit circle repeats itself in all four quadrants. Using these patterns, they evaluate the sine, cosine, and tangent of special angles.

Learners estimate angle measures in this this estimating angle measures lesson. They use an application on their graphing calculator that shows various settings involving angles and then they estimate the angle measure of a clock's...

Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous activity in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also review the...

Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...

We know theorems about circles—now what? Class members prove a theorem, with half the class taking the case where a point is inside the circle and half the class taking the case where a point is outside the circle. The activity then...

Use geometry to improve your pool game! Learners analyze the front half of a pool shot to determine its resulting path. By measuring the angle of incidence, they are able to predict the path of the ball. 

Lead by example. Pupils use software to investigate given measures of sides and angles to determine whether they create congruent triangles. Using the discovered triangle congruences, learners put together proofs.

There's more to a quilt than just a pretty pattern—there's geometry! Explore angle classification using an artistic approach to show your class that quilt designs are really just intricate geometric patterns. Here, scholars create a...

High schoolers explore quadrilaterals in this geometry lesson. They will draw a quadrilateral, measure the angles, and find the sum of the measures of the interior angles using Cabri Jr. The interactive capabilities of Cabri Jr. allow...