Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, students must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Illustrative Mathematics
Sum of Angles in a Polygon
How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Young scholars are asked to divide the...
Illustrative Mathematics
Regular Tessellations of the Plane
Bringing together the young artists and the young organizers in your class, this lesson takes that popular topic of tessellations and gives it algebraic roots. After covering a few basic properties and definitions, learners attack the...
Curated OER
Is This a Rectangle?
How do you show that something is a rectangle? This activity starts with four coordinate points and asks young geometers to explain whether they create a rectangle. Knowledge from both geometry and algebra come into play here, as well...
Teach Engineering
Edible Rovers (High School)
Design and build a rover ... then eat it? This activity has groups of two design and build Mars rovers. The teams determine what instruments they want to include with their rover and plan a budget. They calculate the cost of the body of...
Math Is Fun
Math Is Fun: Solving Triangles
Find guidelines to help you "solve" triangles, which means finding the value of missing sides and angles. Provided are examples of six scenarios in which you can solve a triangle's missing measurements, as well as relevant equations,...
Texas A&M University
Wtamu Virtual Math Lab: Beginning Algebra: Introduction to Problem Solving
A guide to solving problems involving numbers, rectangles, and angles. You'll learn how to employ Polya's four steps: understand the problem, devise a plan, carry out the plan, and look back.
National Council of Teachers of Mathematics
Nctm: Figure This: Math Challenges for Families
Students, teachers, and parents alike will enjoy this challenging math site. It contains a clever brain teaser section plus creative problems related to algebra, geometry, measurement, numbers, statistics, and probability. A Spanish...
Other
All Elementary Mathematics: Trigonometric Equations
This site gives a definition for what a trigonometric equation is, gives a listing of the simplest trigonometric equations, and lists seven main methods of solution of trigonometric equations with examples.