Triangle Teacher Resources

Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...

Construct yourself a winning geometry unit. A set of lessons introduces geometry scholars to constructions and proofs with compasses and straightedges. It also covers triangle congruence through transformations. This is the second of...

Here's some very interesting circles for your very interested pupils. A performance task requires scholars to sketch a pair of orthogonal circles so the centers are the endpoints of one side of a triangle. They draw an additional circle...

In this angles and triangles worksheet, 10th graders solve 10 different problems that relate to various types of reference angles and triangles. First, they determine the value of sine equal to a number of degrees. Then, students write...

A congruent triangles quiz challenges teenage mathematicians to complete a pair of geometric proofs. Each problem includes a picture of the triangles in question, a given set of information, and the five steps needed to finish the proof....

In this geometry worksheet, 10th graders use basic knowledge of congruent triangles (CPCTC) to prove that the given triangles are congruent.  The one page worksheet contains four problems.  Answers are not included. 

Unfortunately for young mathematicians, the world isn't made entirely of parallelograms, triangles, and trapezoids. After first learning the area formulas for these common shapes, learners apply this new knowledge to...

Young mathematicians build an understanding of area and perimeter with their own two hands in a series of interactive geometry lessons. Through the use of different math manipulatives, children investigate the properties of...

Gaining practice in translating a verbal description into a diagram and then an equation is the real point of this similar triangles exercise. Once the diagram is drawn, multiple methods are provided to reach the conclusion. An effective...

Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...

Determine the level of understanding within your classes using a summative assessment. As the final lesson in a 29-part module, the goal is to assess the topics addressed during the unit. Concepts range from linear angle relationships,...

You'd be surprised what you can do with a string! The constraint is the length of string, and the task is to maximize area. Given a series of composite shapes, learners must create a formula for the maximum area for a specified...

Using indirect measurement, this video shows viewers how to find the height of a flagpole. The lecturer employs drawings as well as proportions to solve this problem, explaining each step. A useful resource to aid struggling learners and...

There are shapes everywhere you see! Use a presentation about shapes to encourage young learners to find squares, circles, triangles, and rectangles in a series of pictures. One slide shows kids what the shapes look like, and then a...

Develop an understanding of algebraic sequences through an exploration of patterns. Five leveled problems target grade levels from elementary through high school. Each problem asks young mathematicians to recognize a geometric pattern....

There has got to be a better way; you just have to find it! Given a general binomial to expand with increasing powers, pupils realize that there must be a better way than multiple multiplications. Classmates look for patterns and use...