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.