Mathed Up!
Angles in Triangles and Quadrilaterals
This short video show viewers how to connect the sum of the angles in a triangle to other angle measurements. Pupils determine the missing measures for angles involved with triangles and quadrilaterals. Class members then must explain...
Noyce Foundation
Lyle's Triangles
Try five problems on triangles. Levels A and B focus on shapes that can be created from right triangles. Level C touches upon the relationship between the area of a six-pointed star and the area of each triangle of which it is composed....
Curated OER
Special Triangles and Quadrilaterals
In this special triangles learning exercise, students examine given special triangles. They determine the length of a missing side and/or the measurement of a missing angle for given triangles and quadrilaterals. Students justify their...
Curated OER
Angle Sum of Triangles and Quadrilaterals
In this angle sum instructional activity, students find missing angles of 20 triangles and quadrilaterals. Students find the missing angle in each polygon by using the total degrees of each and given angle measures.
Curated OER
Exploring Polygons and The Greedy Triangle
Excellent lesson plan! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump ropes),...
Curated OER
Developing Formulas for Triangles and Quadrilaterals
In this geometry worksheet, 10th graders determine the area of triangles, parallelograms, trapezoids, kites, and rhombuses. The one page worksheet contains eleven problems. Answers are included.
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of activity, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
Curated OER
Varieties of Quadrilaterals
Young scholars classify quadrilaterals, In this quadrilaterals activity, students watch a video about parallelograms, discuss the different types of quadrilaterals, and complete a worksheet classifying quadrilaterals.
Everyday Mathematics
Mathematics Within: Slope and Triangles
Learners discover a method for determining the slope of a line by creating and comparing similar triangles. They fold coordinate grids to make three similar triangles then measure the sides to compare the relationships between the...
Houghton Mifflin Harcourt
Developing the Concept: Triangles and Quadrilaterals
Exact narrative and examples make this lesson on polygons easy to implement. Through it, your class will learn how to use a protractor and ruler to construct triangles and quadrilaterals according to your directions. Your class will be...
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...
Virginia Department of Education
Exploring Quadrilaterals
Sort this resource into the Use pile. Scholars investigate attributes of quadrilaterals and then use the results to sort and classify the shapes labeling each figure with their properties to justify the classifications.
Curated OER
Let's Explore the World of Triangles and Quadrilaterals!
Second graders explore the features of triangles and quadrilaterals. In this lesson plan on triangles and quadrilaterals, 2nd graders rotate with their group to five different activities all exploring a different aspect of geometry.
Curated OER
Family Activity: Triangles and Quadrilaterals
In this triangles and quadrilaterals worksheet, students solve 7 short answer problems. Students find objects around the house that are constructed from triangles, parallelograms, trapezoids, squares, rectangles. Students sketch the...
Curated OER
Angles, Triangles, Quadrilaterals, Circles and Related
Students 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. Students participate in a manipulative...
Curated OER
The Quirky Quadrilateral
Fourth graders identify and classify different triangles and quadrilaterals. Then they demonstrate an understanding of plane and solid geometric objects and use this knowledge to show relationships and solve specific problems. Students...
Curated OER
Geometry of Triangles - Week 6
In this triangle worksheet, students explore the characteristics of triangles. They find the area of a pentagon, lengths of the sides of a triangle and the area of a quadrilateral. This two-page worksheet contains seven problems.
Curated OER
Isosceles Right Triangle
In this isosceles right triangle worksheet, 10th graders solve and complete 5 different constructions of composition and decomposition. First, they make 4 congruent isosceles triangles with the model on the left. Then, students create...
Curated OER
All Around Triangles and Quadrilaterals
In this triangle/quadrilateral worksheet, students use a centimeter ruler to draw triangles and quadrilaterals with given perimeters. Answers are included on page 2.
Houghton Mifflin Harcourt
Introducing the Concept: Triangles and Quadrilaterals
Guide your geometers through the process of constructing polygons. They learn how to draw triangles, squares, parallelograms, rectangles, rhombuses, and trapezoids with specified angles using a protractor and a ruler. The lesson plan...
EngageNY
Cyclic Quadrilaterals
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
Curated OER
Symmetry Using Polygons
Working on symmetry in your class? If so, this instructional activity might be for you. Learners observe different triangles and quadrilaterals, determine which are symmetrical, draw in the lines of symmetry, and color the symmetrical...
Curated OER
Exploring Characteristics of Triangles
Students draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem: The...