Curated OER
Informal Geometry
Middle and high schoolers solve and complete 29 various types of problems. First, they match each name with its correct formula. Then, students find the length of the missing side and the distance between the two points given. In...
Curated OER
Angles Activities
A series of geometry worksheets have mathematicians constructing, dissecting, overlapping, and measuring as they analyze angles in various contexts. Learners use symmetry and reflections in a compass rose to write instructions on...
Curated OER
Reflections and Equilateral Triangles II
Given the lines of symmetry in an equilateral triangle, your learners find where the pre-image vertices are mapped onto the new image. They explore the properties of equilateral triangles, the impact of reflections, and the idea that the...
National Council of Teachers of Mathematics
How Many Triangles?
For this triangles worksheet, learners problem solve and shade triangles within other triangles. Students complete two problems.
Curated OER
Investigating Lengths of Segments in a Triangle
Pupils explore the midsegment of a triangle in the geometry lesson. They draw and measure the segment joining the midpoints of the two sides of a triangle and compare its length to the length of the third side of the triangle. The...
Curated OER
The Triangle Midsegment Theorem
In this geometry worksheet, 10th graders identify the vocabulary associated with the Triangle Midsegment Theorem and solve problems in which they find the size of a missing angle or segment. The one page worksheet contains nineteen...
Curated OER
Midsegments of Quadrilaterals
High schoolers explore the concept of quadrilaterals as they find the midsegments of quadrilaterals using Cabri Jr. on a graphing calculator. They find midpoints, slopes, angles, and distances of lines and angles.
Curated OER
Midpoints and Bisectors
In this geometry worksheet, students calculate the midpoints of polygons using coordinate pairs. They find the angle bisector, altitude and median of the given triangles. There are 33 questions.
Curated OER
Medians and Altitudes of Triangles
In this geometry worksheet, 10th graders determine if a given segment is a median or altitude of a triangle and use then find the indicated missing length or equation of a line. The two page worksheet contains twenty problems. Answers...
Illustrative Mathematics
Bank Shot
Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....
GeoGebra
Yardwork in Segments
Stretch your knowledge of ratios to the coordinate plane. The interactive allows pupils to set the endpoints of a directed line segment and form a right triangle. Using rubber bands, users visualize the line segment divided into equal...
Curated OER
Isosceles Triangles
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
Curated OER
Triangle Proofs
In this triangle proofs activity, students answer 5 questions about triangles and polygons given certain information. Students then construct 4 triangle or polygon proofs.
Curated OER
Special Segments in Triangles
For this special segments in triangles worksheet, 10th graders solve 5 different types of triangles. First, they identify and describe the four types of segments associated with triangles. Then, students draw and label a figure that...
Curated OER
Triangles
In this triangles instructional activity, 10th graders solve and complete 2 different problems. First, they find the perimeter of each triangle as described. Then, students find the slope of each side and altitude to each side of the...
Curated OER
Geometry of Triangles - Week 6
In this geometry of triangles worksheet, learners find the length of sides, are, and angle measurement of inscribed triangles, pentagons, and midpoint of a line. This two-page worksheet contains seven problems.
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...
Curated OER
Archimedes
In this Archimedes worksheet, students complete and respond to 4 different problems related to different triangles. First, they find the midpoint of each side of a given triangle. Then, students connect the midpoints with the opposite...
Math Worksheets Center
Congruent Triangle Proofs Quiz
A congruent triangles quiz challenges teenage mathematicians to complete a pair of geometric proofs. Each problem includes a picture of the triangles in question, a given set of information, and the five steps needed to finish the proof....
Curated OER
Centroid of a Triangle
Students build on existing knowledge of median and midpoints of triangles. They incorporate their prior knowledge to develop an example of the center of a mass of a triangle. They share their sketches with their classmates.
Illustrative Mathematics
Midpoints of the Sides of a Paralellogram
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Illustrative Mathematics
Reflections and Isosceles Triangles
Geometers explore symmetries of isosceles triangles by using rigid transformations of the plane. They complete four tasks, including congruence proofs, which illustrate the relationship between congruence and rigid transformations. The...
Curated OER
Spatial Relations - Week 9
In this spatial relations worksheet, young scholars identify the number of triangles in a given figure, identify the number of cubes that a plane intersects, and determine the number of line segments in a given cube. This three-page...
Curated OER
Triangles with Collinear Circumcenters
Pupils identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.