EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
EngageNY
Similarity and the Angle Bisector Theorem
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
Mt. San Antonio Collage
Isosceles Triangles and Special Line Segments
Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...
Charleston School District
The Sum of Angles in a Triangle
An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...
Curated OER
Geometry Regents Questions: Isosceles Triangle Theorem
In this isosceles triangle worksheet, high schoolers solve 19 multiple choice and short answer problems. Students use the isosceles triangle theorem to determine unknown angle measures.
Curated OER
Isosceles Triangle Theorem
In this geometry worksheet, students differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.
Curated OER
Angles, Triangles, Quadrilaterals, Circles and Related
Middle schoolers classify angles. In this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Middle schoolers participate in...
Curated OER
Angle Exploration and Classification
Students compare and contrast angles and identify them as acute, obtuse, right, or straight angles. They create rays and angles using uncooked spaghetti, read and discuss key vocabulary terms, and complete a variety of geometry worksheets.
Curated OER
Triangles
In this triangles worksheet, 10th graders solve 12 different problems that include various angles of triangles. First, they determine the measure of an exterior angle. Then, students determine the measure of any of the base angles of an...
Curated OER
Trapezoids
In this trapezoids instructional activity, 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...
Curated OER
Shapes and Angles
Are your geometry whizzes learning about angles and shapes? This online worksheet gives 10 multiple choice questions based on images and word problems. Concepts include deducting angle degree, classifying shapes, and identifying angle...
Virginia Department of Education
Special Right Triangles and Right Triangle Trigonometry
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
Curated OER
Isosceles Triangles
Learners 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.
McGraw Hill
Triangles
After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...
Curated OER
Isosceles Triangles
Students investigate triangles. In this shapes geometry lesson, students define and state the attributes for equilateral, scalene, and isosceles triangles. Students locate the prefix "tri" in a variety of words and make connections with...
Curated OER
The Sum of All Angles
Students add up the different angles using the angle addition postulate. In this geometry lesson, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show their...
Curated OER
Classifying Triangles
In this classifying triangles worksheet, 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 name the sides,...
Curated OER
The Greedy Triangle-Intro to Geometric Shapes
In this geometry lesson, learners read The Greedy Triangle and use geoboards to construct geometric shapes. They identify the number of sides and angles each shape has.
Curated OER
Triangles
In this triangles worksheet, 10th graders solve and complete 23 various types of problems. First, they match the triangle description with the most specific name and write the letter on the line provided. Then, students classify the...
Curated OER
Volume and Surface Area
In this volume and surface area activity, 10th graders solve and complete 12 different types of problems. First, they find the volume of an isosceles trapezoid. Then, students find the volume and total surface area of a sphere. They also...
Curated OER
Perimeter
For this perimeter worksheet, 10th graders solve and complete nineteen various geometry problems. First, they find the length of given segments in addition to the perimeter of a kite. Then, students find the value of a variable so that...
Curated OER
Trigonometry Applications
In this geometry worksheet, 10th graders solve application word problems involving the use or right triangle trigonometry, including angle of elevation or depression. The one page interactive worksheet contains five questions. Hints,...
Curated OER
Interior Angles of Regular Polygons
Students investigate the interior angles of a triangle. In this geometry lesson, students create the formula to calculate the angles inside a triangle. They observe the total sum of a triangles angle on the navigator.
K12 Reader
Classifying Triangles
Bring math and reading informational text together with a reading comprehension lesson. After kids read about isosceles, scalene, and equilateral triangles, they answer five comprehension questions to demonstrate how they can use context...