West Contra Costa Unified School District
Law of Sines
One must obey the sine laws. A lesson plan introduces and derives the Law of Sines for non-right triangles. With examples that use the Law of Sines to determine unknown measures in triangles, the lesson plan checks to see if the Law of...
Willow Tree
Angle Sum Property of Triangles
All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the instructional activity.
Mathematics Assessment Project
Circles in Triangles
Circles, and triangles, and tangents, oh my! In the assessment task, learners first answer questions leading to the radius of an inscribed circle for a given right triangle. They then use the result to independently determine the radius...
Utah Education Network (UEN)
Geometric Figures and Scale Drawings
Scale up your lessons on geometry and ask learners to investigate conditions on triangles, scale drawings, the area and circumference of circles, and angle relationships. The resource includes activities and a homework assignment.
Del Mar College
Formulas for Elementary and Intermediate Algebra
Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more.
EngageNY
Analytic Proofs of Theorems Previously Proved by Synthetic Means
Prove theorems through an analysis. Learners find the midpoint of each side of a triangle, draw the medians, and find the centroid. They then examine the location of the centroid on each median discovering there is a 1:2 relationship....
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 angles, the...
Charleston School District
Similar Triangles
Are they similar? The lesson provides an explanation of the angle-angle criterion for triangle similarity. Several problems allow the class to determine whether the two triangles with the given angle measures are similar or not.
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 similar...
MENSA Education & Research Foundation
Shapes - Kindergarten
Extend scholars' learning experience with a unit consisting of five shape lesson plans, an extension activity, assessment, and rubric. Begin by reading a story about shapes, then conduct an overview and assign pupils' their first...
Los Angeles County Office of Education
Assessment for the California Mathematics Standards Grade 5
Test young mathematicians' knowledge with an assessment aligned to California's fifth grade state standards. The exam covers a multitude of concepts including fractions and decimals, positive and negative numbers, measurement; and how to...
Houghton Mifflin Harcourt
Unit 3 Math Vocabulary Cards (Grade 1)
Reinforce math vocabulary with a set of flashcards. Each card showcases a boldly typed word or a picture representation with labels. The topics are geometry related and include terms such as cones, faces, pyramids, sides, and more!
Los Angeles County Office of Education
Assessment for the California Mathematics Standards Grade 3
Assess scholars' knowledge with a 22-page assessment that covers place value, patterns, probability, estimation, measurement, geometric figures; and their ability to add, subtract, multiply and divide proficiently.
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...
Houghton Mifflin Harcourt
Surprise!: English Language Development Lessons (Theme 2)
Surprise! is the theme of this series of ESL lessons. Cover an array of topics such as where we live, different times of day, shapes, the city and the country, what we do for fun, jobs, and games, all while practicing how to express...
Fayetteville Public Schools
I've Seen That Shape Before
The objectives in the resource allow students to explore the characteristics of simple solid shapes. Youngsters learn to recognize the face shapes, corners, and edges that make up 3-D figures by filling in a chart. Lastly, learners look...
Early Childhood Education
Shape It Up!
The best way to understand shapes is to make them. Young geometers explore basic shapes through a variety of gross motor and fine motor activities. Shape sorting, singing songs about shapes, and eating shape snacks are just a few of the...
Learner
Solid Shapes
A collection of two lessons, kindergartners will identify two-dimensional shapes in solid shapes. They will develop basic knowledge of the components that make up a sphere, rectangular prism, pyramid, cylinder, cone, and cube. Young...
American Farm Bureau Foundation for Agriculture
Shapes on the Farm
Whether you live in the city, the suburbs, or out on the farm, shapes are everywhere in the world around us. Presented with an illustration of a farm, youngsters are tasked with coloring in all of the triangles, rectangles, squares, and...
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
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...
Illustrative Mathematics
Right Triangles Inscribed in Circles I
One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...
K-5 Math Teaching Resources
2-D Shape Cards
Add some visual support to your elementary geometry lessons with this set of printable shape cards. From triangles and squares to octagons and nanogons, this simple resource can be used in countless ways to develop children's knowledge...