Calculate exact trigonometric values using the angles of special right triangles. Beginning with a review of the unit circle and trigonometric functions, class members use their knowledge of special right triangles to find the value...

Why can we see our reflection in a window but not a brick wall? Young physicists learn the Law of Reflection and various light properties that help them answer this and other questions about reflection. Use the PowerPoint to introduce...

When working with matrix multiplication, it all comes back around. The 31st portion of the unit is the third lesson on inverse matrices. The resource reviews the concepts of inverses and how to find them from the previous two lessons....

Breaking the rules is one thing, proving it is another! Learners expand on their previous understanding of congruence and apply a mathematical definition to transformations. They perform and identify a sequence of transformations and use...

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...

Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...

Build right angles using coordinate geometry! Pupils explore the concept of slope related to perpendicular lines by examining 90-degree rotations of right triangles. Learners determine the slope of the hypotenuse becomes the opposite...

Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...

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...

Fifth graders investigate the symmetry of pattern block shapes. Students, working in groups determine whether each shape has line symmetry, rotational symmetry or both kinds of symmetry. Students determine how many lines of symmetry the...

Students define and identify transformation and rotation. In this geometry lesson plan, students define rotations as congruence or isometry. They find the coordinates of an image and pre-image.

Young scholars 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....

Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....

Students discover how the Earth's axis of rotation affects the angle of sunlight and the length of day. They take a survey and give the survey out to family members and friends. They tally their findings and then determine the correct...

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,...

Students explain why compass angles need to be corrected for regional magnetic variation. They observe the difference between magnetic and true north. Each student measures the angle of variation for a town in a different state.

Students describe issues or problems facing African Americans following Reconstruction. They explain possible solutions to these problems suggested in the sources you find, and cite arguments for and against these solutions.

In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.

Students complete a webquest on the various types of symmetry. Using a computer, they explore the concepts of transformational geometry and identify points, segments, lines and planes. They experiment with the rotation of a quadrilateral...

Combine transformations and triangle congruence in a single lesson plan. Scholars learn to view congruent triangles as a rigid transformation. Using triangle congruence criteria, learners identify congruent triangles and the rigid...

Sixth graders identify various angles by using pattern blocks. In this measurement lesson, 6th graders find out how many degrees are in each of the different angles of the various pattern blocks.

Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.

Young geometers investigate two-dimensional figures using coordinate grids. They identify polygons and draw examples of their reflection, rotation, and translation on a coordinate grid. And they complete a worksheet practicing examples...

Learners use the CABRI application for their graphing calculator to rotate, translate, and reflect triangles. They use graphing calculators and follow detailed directions to manipulate triangles in specified ways. There are three...