Help your learners examine triangles. Pupils explore the different sizes and measurements of triangles. They discover triangles can be isosceles or scalene, and examine the attributes of triangles. Here is the website where you can...

Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...

In this constructing triangles online learning exercise, students construct thirteen triangles on paper first and then type in their answers on line. Students can check their answers as they go and the computer calculates the overall...

Students apply the properties of a right triangle. In this triangle lesson, students describe and compare radians to degrees. They solve problems using the properties and ratios of a right triangle.

Young scholars identify positive and negative angles using the Unit Circle. In this pre-calculus lesson, students identify the different angles on a unit circle using the coordinate plane and the four different quadrants as a guide. They...

In this triangle fundamentals worksheet, students identify possible side lengths of triangles. The first three problems give measurements of the sides, students select the combination that is possible in a triangle. The final three...

In this geometry worksheet, 10th graders identify the vocabulary associated with the Triangle Midsegment Theorem and solve problems in which they find the size of a missing angle or segment.  The one page worksheet contains nineteen...

Use this comprehensive pre-instruction assessment tool to focus your teaching where your class needs it most. Multiple choice questions assess your budding geometers' conceptual and vocabulary knowledge, but they do not solve any...

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...

What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...

Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.

Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...

Add up areas of squares to discover the pythagorean relationship. Small groups create right triangles with squares along each side. They calculate the areas of each square and notice the relationship. Groups construct other types of...

Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....

Extend young mathematicians' understanding of area with a geometry lesson on trapezoids. Building on their prior knowledge of rectangles and triangles, students learn how to calculate the area of trapezoids and other...

How do you find the lengths of items that cannot be directly measured? The 13th installment in a series of 16 has pupils use the similarity content learned in an earlier resource to solve real-world problems. Class members determine...

To take the longest path, go around—or was that go over? Class members measure scale drawings of a cylindrical vase to find the height and diameter. They calculate the actual height and circumference and determine which is larger.  

Youngsters draw specified angles when given measurements of other angles and discover traits of angles in similar triangles. This one-page instructional activity contains six multi-step problems.

Concepts are only valuable if they are applicable. An informative resource uses concepts developed in lessons 26 and 27 in a 36-part series. Scholars write equations and solve for missing side lengths for given right triangles....

Measure angles is easy as pi. Pupils review special right triangles to find exact values for trigonometric functions. Scholars learn about radians and how they connect to measurements in degrees. They find exact and approximate values of...

One must obey the sine laws. A lesson introduces and derives the Law of Sines for non-right triangles. With examples that use the Law of Sines to determine unknown measures in triangles, the lesson checks to see if the Law...

Lean a ladder against the wall to create an angle. Class members use an interactive application to determine the angle a ladder makes with the ground. Individuals respond to five questions using inverse trigonometric functions.

A General Certificate of Secondary Education math review has class members make basic constructions. Using a protractor and a ruler along with a compass, pupils develop drawings of triangles with given measurements. Scholars use their...

Mark off the length of the radius around the circle. Using a compass, the presenter shows how to construct a regular hexagon in a circle. Pupils see how triangles formed in the hexagon are equilateral, allowing for the construction to...