Are two angles enough? Given two triangles, the class determines through the definition of similarity and transformations whether the two triangles are similar. Provided with pairs of triangles and measurements, small groups find out...

Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...

Make math class feel like a day at the beach (minus all the sunburns, of course). Given information about a pail, a soup can, and a plastic pyramid mold, pupils calculate the volume of sand that can fit in each. They then design sand...

Conduct indirect measurements three ways. Working in groups, pupils come up with different ways to measure three tall objects indirectly. The teacher provides measurement information requested by the teams, and learners then calculate...

Pairs or small groups work together to determine the height of a tree using similar triangles. Learners make a judgement which direction to let a tree fall to avoid hitting any structures. They then write letters to the principal...

Pupils gather measurements of real-world objects that have slopes. They then plot the measurements and find an equation of a line that fits the measurements. Finally, groups investigate the ADA and determine whether different ramps meet...

Take a similar approach to three dimensions. Pupils develop the relationship between areas of similar objects and see how they relate to the ratio of the sides. Building upon area formulas, small groups put together volume formulas for...

Use rectangles to find distances. Given a rectangle and three associated triangles, pupils determine the area of the triangles. Scholars know the three triangles have equal areas along with the perimeter of the rectangle and two other...

Sometimes the solution is all a matter of perspective. The short assessment task presents a problem to pupils that requires them to make sense of a diagram. Once learners see two similar triangles, the rest of the solution is solving a...

Similar shapes are all about the scale. Given seven problems, pupils use scale factors to determine measurements within similar shapes. While solving the problem, scholars also determine whether two figures are similar and use area and...

Challenge your classes while developing their problem-solving skills. A square is divided neatly into four equal triangles by its diagonals until one diagonal is moved from a vertex to the midpoint of one side. Now, scholars must devise...

What do similar triangles have to do with linear equations? Building on prior knowledge of similar triangles, learners discover that the slope of the sides of similar triangles is the same. They make their discoveries while graphing...

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...

Strike a chord length. The section of a larger playlist on geometry introduces the relationship relating lengths of intersecting chords. Using the relationship, the video shows how to find lengths of segments of the chords.

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.

As if geometry weren't puzzling enough! Give your classes a challenge to solve and watch as they discuss and develop ideas. Part of a larger playlist that explores physics concepts, the video lesson offers a presentation of the puzzle...

Can you hear me from there? Pupils determine the place to build a cell tower on a hill. The class uses constraints and creates a scale drawing on a coordinate system to calculate the exact location of the base of the cell tower.

Bank on geometry to line up the shot. The resource asks the class to determine the location to bank a cue ball in a game of billiards. Using their knowledge, class members determine where to hit the bumper to make a shot and discuss...

Look at proportionality from a parallel perspective. A section of an expansive geometry playlist introduces the Triangle Proportionality Theorem. Using the theorem, the video shows how to determine missing measurements in triangles.

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...

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...

Create similar triangles with a little altitude. A section of an extensive playlist on basic geometry discusses how an altitude of a right triangle creates similar triangles. Using the theorem, the presentation finds unknown side...