New ReviewA 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...

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...

How do you see yourself? Young mathematicians consider whether it's possible to view their whole bodies in a mirror with a length that is half their height. They write a letter to a friend explaining their positions mathematically.

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...

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...

You don't want your bulletin board to be exactly the same as the others. Groups conduct an exploration to see what information is necessary to prove that triangles are congruent in the context of triangular designs on bulletin boards. As...

Congruent sides + congruent angles = congruent triangles. Scholars first create several triangles that satisfy given conditions using straws. They investigate the triangles to see which are congruent, and then they define what it means...

Lead by example. Pupils use software to investigate given measures of sides and angles to determine whether they create congruent triangles. Using the discovered triangle congruences, learners put together proofs.

When the tape measure will not reach, use similarity. An installment of a large playlist on geometry introduces the method of indirect measurement. Using a story of finding the distance to the sun, the video shows how to use similar...

Use the right congruence statement. The video introduces the Hypotenuse-Leg Theorem to prove two right triangles are congruent. Part of a geometry playlist shows that it does not matter which leg to use when proving congruence.

The location of the side makes a difference. One of the videos in a geometry playlist introduces angle-side-angle and angle-angle-side congruence relationships. Using drawings, the video shows how these two congruence statements are...

Gimme three sides, mister! The video introduces the Side-Side-Side Triangle Congruence Theorem. Using segments of different lengths, the portion of a larger playlist on geometry shows that only one triangle can be built.

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...

Provide a large amount of information in a short statement. A segment of a playlist on basic geometry introduces the notation to denote congruence between two figures. The video shows how to read corresponding parts from a congruence...

Combine transformations and triangle congruence in a single lesson. Scholars learn to view congruent triangles as a rigid transformation. Using triangle congruence criteria, learners identify congruent triangles and the rigid...

Given two congruent triangles, the resource provides the definition of congruent triangles and marks the corresponding parts. The portion of a basic geometry playlist shows the triangles are congruent by moving one on top of the other...

Prove it—triangles aren't congruent unless you prove them to be congruent. High school mathematicians learn to prove triangle congruence by using transformations. They see how rigid motions result in congruent sides and angles.

Applying their knowledge of theorems about lines, angles, and triangles, groups build a toothpick and stick bridge to support their text book. The teams use the design process to plan, build, test, and refine their bridge designs. The...

See how parallelograms can produce congruent triangles. Given a diagram of a parallelogram, scholars must show that two triangles are congruent. The triangles are made from the diagonals of the parallelogram.

Do transformations always result in congruent figures? Using a given pre-image triangle, scholars perform two separate transformations on the triangle. Based on the images, they decide whether the triangles are congruent.

Cut straight to the proof. Given cutouts of different quadrilaterals, pupils draw diagonals. Learners cut up the figures along the diagonals to see whether they bisect each other. Scholars develop a geometric proof for the property they...