Curated OER
A Rectangle in the Coordinate Plane
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.
Shodor Education Foundation
Pythagorean Theorem
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...
EngageNY
Perimeter and Area of Polygonal Regions in the Cartesian Plane
How many sides does that polygon have? Building directly from instructional activity 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...
Curated OER
Getting It Right! An Investigation of the Pythagorean Theorem
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...
Hotchalk
Triangle Sum Theorem
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...
EngageNY
Searching a Region in the Plane
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...
Curated OER
Pythagorean Theorem
In this measurement lesson, learners examine the Pythagorean Theorem, perimeter, and areas of right triangles. They record their measurements and research their findings on a grid.
EngageNY
Distance on the Coordinate Plane
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...
Virginia Department of Education
Circles in the Coordinate Plane
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...
Illustrative Mathematics
Shortest Line Segment from a Point P to a Line L
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 class...
Virginia Department of Education
Arc Length and Area of a Sector
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...
EngageNY
Writing the Equation for a Circle
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 activity then provides an exercise set for learners to...
EngageNY
Segments That Meet at Right Angles
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...
EngageNY
Comparing the Ratio Method with the Parallel Method
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...
Curated OER
The Pythagorean Theorem, the Distance Formula, and Slope
Students explore the concept of the Pythagorean Theorem. In this Pythagorean Theorem lesson, students derive the distance formula and slope of a line from the Pythagorean Theorem.
Curated OER
Linear/Planar Geometry - Week 5
In this linear and planar geometry worksheet, pupils use the Pythagorean Theorem, equation of a line, slope of a line and area formulas to solve problems. This three-page worksheet contains seven problems.
EngageNY
Distance and Complex Numbers 1
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...
Curated OER
Pythagorean Theorem
Students investigate the Pythagorean Theorem. In this seventh through twelfth grade geometery lesson, students explore the Pythagorean Theorem and its converse and use it to find the length of the missing side of a right triangle.
Curated OER
Pythagorean Theorem
Students solve problems using the Pythagorean Theorem. In this geometry lesson plan, students identify the sides and angles of a right triangle. They find the different trigonometric ratios and solve using sine, cosine and tangent.
Alabama Learning Exchange
Coordinate Geometry
Where do the coordinates lead? As children brainstorm ways to find the location of different buildings, they learn about coordinate points and how to use them to locate areas on a grid or map. They practice using ordered pairs by playing...
EngageNY
Perimeter and Area of Polygonal Regions Defined by Systems of Inequalities
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...
EngageNY
Criterion for Perpendicularity
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 endpoints and...
EngageNY
Lines That Pass Through Regions
Good things happen when algebra and geometry get together! Continue the exploration of coordinate geometry in the third activity in the series. Pupils explore linear equations and describe the points of intersection with a given polygon...
Curated OER
Linear/Planar Geometry - Week 5
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...