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...
Curated OER
Complex Distance
Have learners graph complex numbers to gain a visual and mathematical understanding of the distance and the midpoint between two complex numbers. This lesson is short, but to the point, and addresses an important complex number...
Teach Engineering
Matching the Motion
It is not always easy to walk the straight and narrow. In the sixth portion of a nine-part unit, groups actively recreate a graph depicting motion. Individuals walk toward or away from a motion detector while trying to match a given...
Illustrative Mathematics
Placing a Fire Hydrant
Triangle centers and the segments that create them easily become an exercise in memorization, without the help of engaging applications like this instructional activity. Here the class investigates the measure of center that is...
Illustrative Mathematics
Dilating a Line
High School geometers verify through experimentation certain properties about dilations. This multi-step problem challenges them to construct examples of dilations to verify specific facts, the final step provides an opportunity to more...
Illustrative Mathematics
Are They Similar?
Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...
Curated OER
Taxi!
Your young taxi drivers evaluate and articulate the reasoning behind statements in a conceptual task involving linear data. The given data table of distances traveled and the resulting fare in dollars is used by learners to explore...
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...
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,...
101 Questions
Best Reflection
Which is the best reflection of them all? Given four diagrams, pupils determine which one shows the most accurate reflection of a quadrilateral. Two images provide the distances of each vertex from the line of reflection, as well as the...
Curated OER
Circumcenter of a Triangle
Your geometry learners will discover and show the construction of the circumcenter of a triangle. Guided by the steps in the activity, they construct perpendicular bisectors of each side that have a point of concurrency called the...
Illustrative Mathematics
Satellite
Learners practice relating rules of trigonometry and properties of circles. With a few simplifying assumptions such as a perfectly round earth, young mathematicians calculate the lengths of various paths between satellite and...
Illustrative Mathematics
Robot Races
Analyze data on a graph to answer three questions after a robot race. Learners practice comparing ratios and reading points on a graph. Answers may vary on the last question based on accuracy of graphing. Use the lesson along with...
Other
Git: What Is the Slope Intercept Form of a Line?
Not only does this site show what the slope-intercept form is, but it helps you find the slope and the intercept of a line. There is also additional information on parallel lines, parametric form, and the distance between two points.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Point, Line, Planes, Angles
Practice using your graphing calculator for drawing and labeling points, lines, planes, and angles. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each...
Texas Instruments
Texas Instruments: Finding the Shortest Path
Students discover the shortest distance light travels from an object to the human eye, as the light from the object reflects off a single mirror. In the process they learn about reflection in a line, congruent angles, angle bisectors,...