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....
University of Utah
Geometry Part 2: Measurement in 2- and 3-Dimensions, Plane Sections of Solids
What kind of tree does a math teacher climb? A geometry! Here is a lesson that includes all the geometry resources you could ever wish for in one comprehensive workbook. Class members demonstrate what they have learned by determining the...
Utah Education Network (UEN)
Geometry
Shape one's understanding of geometry using the resource. The sixth of seven chapters in 6th Grade Math focuses on geometry principles. Future mathematicians learn to find the area of parallelograms, trapezoids, triangles, and other...
National Council of Teachers of Mathematics
Stitching Quilts into Coordinate Geometry
Who knew quilting would be so mathematical? Introduce linear equations and graphing while working with the lines of pre-designed quilts. Use the parts of the design to calculate the slope of the linear segments. The project comes with...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Shodor Education Foundation
InteGreat
Hands-on investigation of Riemann sums becomes possible without intensive arithmetic gymnastics with this interactive lesson plan. Learners manipulate online graphing tools to develop and test theories about right, left, and midpoint...
West Contra Costa Unified School District
Finding the Equation of a Circle
Tired of going around and around for a resource on circles? Scholars determine the general equation of a circle on a coordinate plane, then participate in an activity matching equations to the radii and centers of the circles they...