EngageNY
An Area Formula for Triangles
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
Alabama Learning Exchange
What You Know About the Bermuda Triangle?
Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.
PBS
Accessible Shapes
All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....
Los Angeles County Office of Education
Assessment For The California Mathematics Standards Grade 6
Test your scholars' knowledge of a multitude of concepts with an assessment aligned to the California math standards. Using the exam, class members show what they know about the four operations, positive and negative numbers, statistics...
EngageNY
End-of-Module Assessment Task: Pre-Calculus Module 4
Challenge your scholars to show what they know about the Law of Sines, Law of Cosines, and inverses. The six-question assessment is the last in a series of 16. Pupils find the area of triangles and show that the Law of Sines and Law of...
Los Angeles County Office of Education
Assessment For The California Mathematics Standards Grade 4
Have scholars show what they know with a 20-page assessment aligned to the California State Standards. The test covers concepts such as large and whole numbers, all four mathematical operations, fractions, decimals, geometric figures,...
Houghton Mifflin Harcourt
Unit 6 Math Vocabulary Cards (Grade 5)
Acute angles, nets, and vertices are only a few terms that a set of flash cards includes. Among the 108 cards, two types are available; word cards printed in bold-faced lettering, and corresponding definition cards equipped with an...
Oswego City School District
Regents Exam Prep Center: Area of a Triangle and Parallelogram Using Trig
How can trigonometry be used to find the area of a triangle or parallelogram? Does the triangle need to be a right triangle, and how accurate can the results possibly be? The answers to these questions are found here along with several...
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Properties of Triangles
This lesson focuses on the properties of triangles, a closed shape that has three sides, three vertices, and and three internal angles. There are different types of triangles such as a right triangle, obtuse, and acute based on the...
Khan Academy
Khan Academy: Area of Triangles
Practice finding the area of right, acute, and obtuse triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.