EngageNY
Equations for Lines Using Normal Segments
Describing a line using an algebraic equation is an essential skill in mathematics. The previous lesson in the series challenged learners to determine if segments are perpendicular with a formula. Now they use the formula to determine...
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...
Barton Math Class
Parallel and Perpendicular Lines Worksheet
With the focus being on parallel, perpendicular, or neither type, practice with three different types of problem solving. Learners start with a simple skill of determining the relationship between slopes and then work towards creating...
Mathematics Vision Project
Module 6: Congruence, Construction, and Proof
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This unit...
Mathematics Vision Project
Module 7: Connecting Algebra and Geometry
The coordinate plane links key geometry and algebra concepts in this approachable but rigorous unit. The class starts by developing the distance formula from the Pythagorean Theorem, then moves to applications of slope. Activities...
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
Illustrative Mathematics
A Midpoint Miracle
Young geometers develop one of the fundamental properties of quadrilaterals (connecting side midpoints gives a parallelogram) in this short but thought-provoking exercise. Using a combination of hands-on techniques and abstract algebraic...
Curated OER
Is This a Rectangle?
How do you show that something is a rectangle? This activity starts with four coordinate points and asks young geometers to explain whether they create a rectangle. Knowledge from both geometry and algebra come into play here, as well...
Curated OER
Connecting Algebra and Geometry Through Coordinates
This unit on connecting algebra and geometry covers a number of topics including worksheets on the distance formula, finding the perimeter and area of polynomials, the slope formula, parallel and perpendicular lines, parallelograms,...
Curated OER
Unit Squares and Triangles
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle and angle...
Curated OER
Parallel and Perpendicular Lines
Young geometers get some solid skills practice in evaluating slopes. Beginning with the basics of slope through two points and progressing through properties of parallel and perpendicular lines, the building of skills is gradual and...
Curated OER
Triangles Inscribed in a Circle
Are you tired of answers without understanding? Learners can give a correct response, but do they really understand the concept? Have young mathematicians think deeper about linear functions, angles, and formulas in algebra. Learners are...
Curated OER
Creating a Midpoint Quad
Using a TI Navigator to drag quadrilaterals around to create different shapes, students learn how to draw midpoints in their quadrilaterals. In this geometry instructional activity, students solve problems using the properties of...
Curated OER
Investigating the Slopes of Parallel and Perpendicular Lines
High schoolers investigate parallel and perpendicular lines. They use Cabri Jr. to construct and explore the relationships between the slopes of parallel and perpendicular lines. The drawing and measurement tools available with Cabri Jr....
Curated OER
Pyramid Activity
Pupils explore the concept of pyramids. They determine if two sides of a pyramid are perpendicular using a graphing calculator, then discuss parallel and perpendicular lines and how to determine if two lines are parallel or...
TeachEngineering
Teach Engineering: Graphing Equations on the Cartesian Plane: Slope
The lesson teaches students about an important characteristic of lines: their slopes. Slope can be determined either in graphical or algebraic form. Slope can also be described as positive, negative, zero or undefined. Students get an...
Texas Education Agency
Texas Gateway: Making Conjectures About Parallel and Perpendicular Lines
The student will verify theorems about angles formed by parallel lines cut by a transversal and apply these relationships to solve problems.
Texas Education Agency
Texas Gateway: Coordinate Geometry: Parallel and Perpendicular Lines
Given characteristics of two lines, such as slopes and equations, the student will determine whether the lines are parallel, perpendicular, or neither.
Paul Dawkins
Paul's Online Notes: Algebra: Lines
Detailed math tutorial features notes and examples that discuss graphing lines and introduces the concept of slope, the standard form of the line, the point-slope form, slope-intercept form, and parallel and perpendicular lines.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Parallel and Perpendicular Lines
Get independent practice working with parallel and perpendicular lines. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
Wolfram Research
Wolfram Math World: Perpendicular Bisector
MathWorld's definition of a perpendicular bisector, with illustrations to show the different uses of the perpendicular bisector.
Texas Instruments
Texas Instruments: Parallel or Perpendicular What's Your Inclination?
This activity has students discover the relationship between parallel and perpendicular lines and their slopes. After constructing these objects using CABRI Geometry II for the TI-89, slopes are measured. [Requires Adobe Reader.]
Texas Instruments
Texas Instruments: Geometry: Parallel and Perpendicular Slopes
This activity will help students understand the relationship between the slopes of parallel and perpendicular lines.
Texas Instruments
Texas Instruments: Parallel and Perpendicular Slopes
This activity is for use as a formative assessment tool after the introduction and overview of parallel and perpendicular slopes.