Curated OER
Congruent Triangles
In this congruent triangles worksheet, 10th graders solve and complete 10 different problems that involve various congruent triangles. First, they determine the length of the third side given the other two. Then, students determine the...
Curated OER
Quadrilaterals and their Diagonals
In this quadrilaterals and their diagonals worksheet, 10th graders solve 3 problems related to determining various types of quadrilaterals. First, they draw the diagonals for each of the quadrilaterals and determine for which the...
Curated OER
Trapezoids
In this trapezoids worksheet, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...
Curated OER
Classifying Triangles
In this classifying triangles instructional activity, 10th graders solve 9 various problems that classify triangles into categories. First, they refer to the figure shown of an isosceles triangle with two line parallel. Then, students...
Curated OER
Inscribed Angles
In this inscribed angles activity, 10th graders solve 13 various types of problems related to inscribed angles in geometry. First, they identify a circle illustrated and each arc of the circle. They, students find the measure of each...
Curated OER
Trapezoids
In this trapezoids worksheet, 10th graders solve 10 different types of problems related to measuring trapezoids. First, they identify the isosceles trapezoid on the sheet with the bases MA and TH. Then, students use the given information...
Curated OER
Triangles and Quadrilaterals
In this triangles and quadrilaterals worksheet, 10th graders solve 6 different problems related to using triangles and quadrilaterals in informal geometry. They determine how many lines of symmetry an equilateral triangle and an...
Curated OER
Classifying Triangles
In this classifying triangles instructional activity, 10th graders solve 6 different problems related to the classification of triangles either by their angles or by their sides. First, they use a protractor and a ruler to draw triangles...
Curated OER
Geometry and Triangles
In this geometry triangles activity, students first determine how many degrees are found in one half and in three-fifths a revolution. Then they find the supplement of the two angles given and the radius of a circle. Students also...
Curated OER
Geometry of Triangles - Week 6
In this geometry of triangles worksheet, students 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
Types of Triangles
As a reference sheet for types of triangles, this worksheet would be good for students to keep in their binder or to take notes about; however, it would need to accompany an existing lesson as there is no activity beyond basic...
Curated OER
Constructions of Isosceles and Equilateral Triangles
Students explore the difference between drawing and constructing a triangle utilizing The Geometer's Sketchpad on the computer. They create, develop and script constructions for both isosceles and equilateral triangles. Each student has...
Curated OER
Angles
In these angles worksheets, students complete several activities for angles. Students complete 34 problems about angle measurement.
Curated OER
Geometry Puzzle
In this geometry puzzle worksheet, learners identify and complete a puzzle that includes 7 different geometrical shapes. They identify and name each shape listed at the bottom. Then, students label every shape in the puzzle with the...
Curated OER
Triangle Challenge
In this triangles activity, students identify and name 3 different types of triangles. First, they determine the number of right triangles in the figure shown on the sheet. Then, students determine the number of equilateral triangles and...
Curated OER
Triangle Angle Sort
In this triangle and angle worksheet, 10th graders identify 36 different angles and triangles illustrated on the sheet. First, they define the vocabulary to include equilateral, scalene, right, and isosceles triangle. In addition, they...
Curated OER
Symmetry
Sixth graders explore symmetry and discuss the difference between a rotation and reflection. Using hands-on activities, such as folding paper shapes, they discover how to find the lines of symmetry and symmetrical characteristics. As a...
National Council of Teachers of Mathematics
Nctm: Illuminations: Tube Viewer Simulation
A computer simulation of viewing through various lengths of tubes at different distances. The simulation also has an exploration of focus questions. [Requires Java.]
National Council of Teachers of Mathematics
The Math Forum: Triangle Formulas
Investigate the geometric definitions of triangles, focusing upon equilateral, isosceles, right, and scalene with detailed drawings and appropriate formulas for each. This site has links to more information on triangles.
Oswego City School District
Regents Exam Prep Center: Isosceles Triangle Theorem
Material to supplement instruction on isosceles triangles: a lesson with related theorems and examples; an online practice quiz for students to take and check their answers; and guidelines for proving the isosceles triangle theorem.
Texas Instruments
Texas Instruments: Isosceles Triangle
In this activity, students construct isosceles and equilateral triangles. They discover that if two sides of a triangle are congruent, then the angles opposite them are congruent. They understand that an equilateral triangle is also...
Texas Instruments
Texas Instruments: Isosceles Triangles
Questions on the basic characteristics of an isosceles triangle
University of Cambridge
University of Cambridge: Nrich: Triangles to Tetrahedra
Given an unlimited number of a specific type of equilateral, isosceles, and right triangles create as many tetrahedra as are possible. Includes printout.
Khan Academy
Khan Academy: Find Angles in Isosceles Triangles
Find missing angles in isosceles triangles given just one angle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.