Curated OER
Concurrent Lines in Triangles
Students explore the concept of concurrent lines in triangles. In this concurrent lines in triangles lesson, students work in groups to investigate properties of concurrent lines in acute, right, and obtuse triangles. Students use a...
EngageNY
Special Lines in Triangles (part 2)
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
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...
Curated OER
NUMB3RS Activity: Regular Ploygon Centroids
Students investigate geo-profiling. In this secondary mathematics instructional activity, students use geo-profiling to determine the most probable location of a criminal. Students find the centroid of a polygon where the vertices...
Curated OER
Bisectors of Triangles
In this geometry worksheet, 10th graders solve problems involving the perpendicular bisectors and angle bisectors of a triangle and their points of concurrency. The one page worksheet contains sixteen questions. Answers are included.
Curated OER
Incenter of a Triangle
Tenth graders find the incenter of a triangle. For this geometry lesson, 10th graders define the way to create an incenter with an angle bisector. They differentiate between incenter and incircle.
Curated OER
The Search for Pythagoras' Treasure
Students identify and define properties of triangles. In this geometry lesson, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.
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 lesson. Here the class investigates the measure of center that is equidistant to the three...