Three letter-sized mini posters can be displayed in your elementary geometry class when teaching about angles. One provides information about degree measurement and additive properties, and the other two define acute, right, obtuse,...

Highlighting the basics of working with angles, this resource could provide a sound introductory activity for students who are beginning to learn about angles. Eager mathematicians will be introduced to the terminology associated with...

Fourth and fifth graders identify three types of angles, recognize that angles are measured in degrees, measure angles using protractors or angle rulers. They classify angles as a class, classify angles on pattern blocks, and complete a...

Even though there is a wide variety of different triangles in the world, knowing a single equation allows us to find the area of each and every one of them. Follow along with this step-by-step presentation as Zoe clearly models how to...

A trigonometric ratio is a ratio between two sides of a right triangle. In this problem, find sin(A) in the given right triangle. Use the ratio of the opposite side over the hypotenuse.

What are all the parts of a right triangle called? What makes it a right triangle? Legs? Triangles have legs? Hypotenuse? Pythagorean Theorem? The instructor diagrams and identifies all the parts of a right triangle for you.

The formula for the area of a triangle is: area equals one half the base times the height. If you have been given these two values then all you need to do is plug them into the formula and solve. Don't forget to write the correct ending...

Trapezoids can be tricky! Break down the process of finding the area of a trapezoid with an engaging math video. Learners explore area formula and shown exactly how to plug in information, solve, and simplify. 

Supplementary, obtuse, acute, complementary angles. It's good to know what all of these mean, but let's focus on one at a time. Complementary angles always add up to 90 degrees. So if given one angle in a complementary angle problem, the...

What are the things that make a shape a cone? Here's a list of things that define a cone: base, height, vertex, radius, curved side. Are you familiar with all these terms? The teacher diagrams a cone and identifies all the components in...

Use the Pythagorean Theorem formula to check if this given triangle, with the given lengths of each side, is a right triangle. It's as simple as plugging the given values into the formula and doing the math to see if the solution checks...

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...

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...

Trapezoids can be tricky. Break down the process of finding the area of a trapezoid with this video! Viewers are given information about the area formula and shown exactly how to plug in information, solve, and simplify. This is a...

Are you working on the distance formula? Derive the distance formula and help your learners by showing them the logic behind the distance formula. This practical video should help conceptual understanding and is appropriate for in-class...

Get out those protractors! Once geometers can identify obtuse, acute, right, and straight angles, get them to measure and draw their own. There are six boxes here, each with an angle measurement. Learners use a protractor to draw the...

Are these angles greater than, less than, or equal to a square corner? Using a visual guide, young geometers label 16 angles into one of these three categories. Use this before introducing the terms acute, obtuse, and right angle, but...

Some shapes have square corners, and some do not. Scholars participate in a sorting activity as they determine if these 12 shapes have square corners, categorizing them based on this attribute. Encourage geometers to draw the square into...

Take a look at these angles: What kind are they? Give mathematicians practice identifying obtuse, acute, and right angles in this categorizing activity. Each type is pictured and explained at the top, and scholars examine nine sample...

Here is a geometry lessonwhich invites learners to create models using their knowledge of lines, segments, rays, and angles. This lesson reinforces geometric vocabulary and concepts through practical application, it also includes...

Elementary schoolers find the missing angle in a complementary angle.  This two-page instructional activity contains six problems. Answers are provided.

An interactive assignment displays two example angles to teach how to measure them. When you click on the angles, a protractor appears! As practice, learners view a set of angles, estimate the size of each, and then enter the degrees in...

Is it a line, line segment, ray, or angle? Identifying geometric figures is the focus. In addition to identification, learners recognize right angles or tell if an angle is less than or greater than a right angle. They tell if lines are...

Upper graders solve ten multiple choice problems about angles and measuring angles.