A quadrilateral is drawn on the coordinate plane, and eighth grade geometers find the length of each side and the diagonals by applying the Pythagorean theorem. 

How many sides does that polygon have? Building directly from lesson number eight in this series, learners now find the area and perimeter of any polygon on the coordinate plane. They decompose the polygons into triangles and use Green's...

Programming a robot is a mathematical task! The activity asks learners to examine the process of programming a robot to vacuum a room. They use a coordinate plane to model the room, write equations to represent movement, determine the...

To work through the complexity of coordinate geometry pupils make the connection between the coordinate plane and the complex plane as they plot complex numbers in the 11th part of a series of 32. Making the connection between the two...

What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...

Most adults remember learning about the Pythagorean theorem, but they don't all remember how to use it. The emphasis here is on developing an intuitive understanding of how and when to use the theorem. Young mathematicians explore...

When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...

Learners construct a variety of right triangles using a right-angled set square, cutting corners from pieces of paper or cardboard, and using dynamic geometry software. They measure the sides of these various right triangles and record...

Make the connection between the distance formula and the equation of a circle. The teacher presents a lesson on how to use the distance formula to derive the equation of the circle. Pupils transform circles on the coordinate plane and...

Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...

Small groups work through two guided activities to derive the distance and midpoint formulas for the coordinate plane. The activities begin with concrete examples and move to abstract.

Apply the Pythagorean Theorem to coordinate geometry. Learners find the distance between two points on a coordinate plane by using the Pythagorean Theorem. The vertical and horizontal change creates a right triangle, which allows...

Can segments be considered perpendicular if they don't intersect? Learners look at nonintersecting segments on the coordinate plane and make conclusions about the lines that contain those segments. They determine if they are...

In this measurement lesson plan, learners examine the Pythagorean Theorem, perimeter, and areas of right triangles. They record their measurements and research their findings on a grid.

One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the...

Your Geometry learners will collaboratively prove that the tangent line of a circle is perpendicular to the radius of the circle. A deliberately sparse introduction allows for a variety of approaches to find a solution. 

Make your classroom interesting by teaching or assessing through tasks. Deepen the understanding of Geometry and motivate young mathematicians. The task uses investigation with tennis balls and their container to prompt learners to...

Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...

You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency,...

Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...

Students view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Students use pegboards and string to create more...

In this plane geometry worksheet, students combine the basis of plane geometry and linear problems to solve problems. They determine total surface area, the length of a line, and the sum of the edges of a three-dimensional figure. This...

Circles aren't functions, so how is it possible to write the equation for a circle? Pupils first develop the equation of a circle through application of the Pythagorean Theorem. The lesson then provides an exercise set for learners to...

The Pythagorean Theorem is a geometry pupil's best friend! Learners explain the equation a1b1 + a2b2 = 0 for perpendicular segments using the Pythagorean Theorem. They are able to identify perpendicular segments using their...