Why use six corresponding parts when three will suffice? The second of five lessons in the Geometry - Triangle Congruence unit focuses on the SSS and SAS triangle congruence criteria. By watching a video, scholars learn how to identify...

Take time to tackle triangles. Scholars watch a video that first reviews the types of triangles. They then investigate the Isosceles Triangle Theorem and see how to apply it to solve problems. At the end, individuals also learn how to...

Triangles bring sums to geometry. The lesson presents two theorems dealing with the angles of a triangle. Pupils learn about the Triangle Sum Theorem and the Exterior Angle Theorem, and then apply the theorems to create equations and...

Viewers of an entertaining short video have an opportunity to save the world! All they have to do is solve the unstoppable blob riddle. Acute learners will have no problem with this problem.

Creating a triangles is as easy as 5, 6, 7. Using a ruler and compass to measure off lengths, a short video shows how to construct a triangle with three specific side lengths. The example creates a triangle with side lengths of 5 cm, 6...

Two sides and an angle ... a triangle it makes. Given the measure to two sides and the angle between them, the narrator of a short video shows how to draw a triangle with a ruler and protractor. Pupils use handouts to practice the newly...

The narrator of a short video explains the steps in constructing a triangle given the measure of two angles and the length of the side between the angles. The resource provides opportunities for pupils to practice the skill with two...

Flat, positively curved, or negatively curved ... what is the true shape of the universe? Scientists use many indirect measurements to base their theories on the shape of the universe. Using an installment from the SciShow Space series,...

Young mathematicians learn about the many theorems related to congruent triangles. The video allows them to stop and replay the content as many times as needed to take notes. Extra practice problems work as reinforcement for each skill...

Young mathematicians observe a geometric proof using a short video. They see each part of the diagram clearly labeled and the simple math written off to the side. The new knowledge helps them solve additional problems independently.

Base times height or one half base times height ... area formulas are pretty predictable! Given the base and height dimensions of a triangle, a video lesson explains the process of finding the area. Learners have the opportunity to...

Base a lesson on an informative video perfect for expanding your class's knowledge of triangles. Young mathematicians watch a brief YouTube video that teaches how to solve for the base of a triangle given its height and area. It also...

Go from a parallelogram to a triangle. A segment of an extensive playlist on basic geometry shows the derivation of the formula for the area of a triangle. The resource works examples that require finding a missing side or height to...

Judging by the sides, things appear similar. A portion of a larger playlist on geometry introduces the Side-Side-Side Similarity Theorem. The video shows how to use the lengths of sides to determine whether triangles are similar.

Balance the knowledge of intersecting medians. Using examples, the portion of a geometry playlist introduces the centroid. A video describes the property of the location of the triangle medians' point of concurrency. 

Get right up and split it in half. Using a diagram, the video provides the definition of a perpendicular bisector. The portion in a playlist on basic geometry explains perpendicular bisector of a segment and of triangle sides properties.

Two sets of congruent angles leads to three. Using diagrams of two triangles, the presentation intuitively shows that if two sets of angles are congruent, the third set is too. The portion of a geometry playlist uses that information to...

Use the opposite to organize angles or sides. The video provides the relationship of angle measures based on the lengths of sides in a triangle and its converse. Using two triangles, the segment of a larger playlist on geometry shows the...

Can any three lengths make a triangle? One of the videos in a playlist on basic geometry introduces the Triangle Inequality Theorem. Using three given lengths, the presentation illustrates the restrictions on lengths of any side of a...

Find the location of altitudes—from any elevation! The video presents the definition of an altitude of a triangle. By drawing examples, the segment of a larger geometry playlist highlights the location of altitudes of various triangle...

If two sets of angles are equal, the third set is too. An informative portion of a playlist on geometry develops the Third Angle Theorem for triangles. Using the theorem, the presenter shows how to determine the measure of missing angles...

Use half the length to connect the midpoints. A section of a playlist on geometry introduces the concept of a midsegment of a triangle and how to find it. The video states the properties of the midsegment which make up the Midsegment...

SAS is not just a spy organization. A section of an extensive geometry playlist introduces a way to show two triangles are congruent, SAS. Using diagrams, the video provides an explanation by showing only one triangle is formed with two...

Use the inside to find the outside. The resource presents two theorems dealing with exterior angles of a triangle. Using the two theorems, the segment from a larger geometry playlist works problems to solve for angle measures.