Your geometry learners determine the measure of remaining angles in sets of three given that the other two are complementary or supplementary. From a diagram, they identify which angles are supplementary, complementary or congruent from...

You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their...

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...

The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.

How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...

Approach the lesson from the right angle. A discussion-based lesson leads helps learners understand angles in terms of rotation. Individuals use manipulatives to explore the properties of angles and learn how to name them. The lesson is...

All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the instructional activity.

Show your class that finding angle measures is a regular calculation with a resource that provides 12 problems dealing with the measures of angles in regular polygons. Pupils use formulas for the sum of measures of angles in a polygon to...

Lead the class in a Greek history lesson 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...

Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...

Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the...

Come look at trigonometry from a different angle. To begin a simple activity, scholars view a video of someone using a clinometer to find the angle of elevation to the top of a building. They then use a diagram that shows the building's...

Pupils work on seven problems that use equations and expressions to solve geometry problems. The questions range from finding equivalent expressions to finding areas and volumes of figures. Learners apply their knowledge of angle...

Use right triangles for more than just mathematical problems. The first two lessons of a unit ask pupils determine distances between cities by using the Pythagorean Theorem and a map. To cement understanding, learners use trigonometric...

Go around the unit circle and create triangles. Pupils move a point around the unit circles to visualize the triangle associated with the angle in standard position. The three main trigonometric functions are defined in terms of the legs...

Scholars work through three different activities applying their knowledge of total internal reflection (TIR). First, they simply identify which diagrams create TIR and which don't. Next, they match different types of boundary behaviors...

Students identify interior and exterior angles of polygons. In this geometry lesson, students add interior and exterior angles of polygons. They use angle theorems to solve the problems.

In this geometry worksheet, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior angles of a...

Label angles of parallel lines to analyze the angles created by a transversal and two parallel lines. They graph their lines and observe the similarity and difference in the angles.

In this applied trigonometry problems instructional activity, high schoolers solve 12 short answer word problems. Students use trigonometric ratios to find angles of elevation and depression. High schoolers find distances between objects...

For this angle sum worksheet, students find missing angles of 20 triangles and quadrilaterals.  Students find the missing angle in each polygon by using the total degrees of each and given angle measures.

In this trigonometric ratios worksheet, students solve 20 short answer and multiple choice problems.  Students use trigonometric ratios, the angle of depression, and angle of elevation to find missing side lengths of angles of a...

In this refraction through a triangle worksheet, students use a given diagram of light striking a triangular piece of plexiglass to determine the light ray's angle of incidence, the ray's angle of refraction, they use Snell's Law to...

In this refraction through a circular disk instructional activity, students are given a diagram of a circular disk of leaded glass with light striking it. Students use the diagram to find the angle of incidence of the light, the angle of...