Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...

How did ancient peoples determine the height of really tall objects? Young scientists and mathematicians explore the concept of using shadows to measure height in a hands-on experiment. Paired pupils measure shadows, then calculate the...

Scientists could measure the diameter of the sun before they knew its distance. Scholars construct a simple mirror box to measure the diameter for themselves. They compare this measurement with the official size, listed in a...

Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...

The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure. 

Travel the world instantly—and learn about math along the way. Using pictures of famous places taken from Google Earth, scholars look for parallel and perpendicular lines based on slope and angle measurements. They also calculate...

Using patty paper, classes determine that only one triangle is possible when given two specific angle measures and a side length. As the 10th instructional activity in the series of 29, young math scholars add these criteria to those...

Can any three side lengths create a triangle? Your classes tackle this question and more in the 11th lesson of the 29-part module. Through modeling with patty paper, individuals discover the relationship between the lengths of the sides...

Polygons — it's all about the angles. Groups work with dynamic geometry software to find the sum of the measures of the angles of various polygons. After finding the information for several polygons, the groups generate a formula that...

The third activity in the series of 29 asks learners to identify types of angles to verify angle relationships. They find unknown measures using vertical, adjacent, complementary, supplementary, and 360-degree angles.

They say a picture is worth a thousand words—and your pupils may agree after this instructional activity! They read a geometric description and create a diagram from that description. Their diagrams help them find unknown measures based...

Challenge your classes to combine geometric and algebraic concepts with an activity that builds on concepts learned in the first three lessons of the series. The fourth part asks scholars to identify geometric angle relationships and use...

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,...

Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...

Can people really measure time just by using the sun? Scholars venture outside on a nice, sunny day to build sundials and learn how people measured time 600 years ago. The class builds two different sundials while gaining practice with...

Representing data is as easy as pie. Class members construct pie charts given a frequency table. Individuals then determine the size of the angles needed for each sector and interpret the size of sectors within the context of frequency....

How high will it fly? Pairs build straw rockets and launch them at different angles and determine the height and horizontal distance of the flight path. Teams make conjectures about how the angle affects the measured distances and use...

Show budding mathematicans how to find the sine of pi over 12. The third lesson in a series of 16 introduces the addition and subtraction formulas for trigonometric functions. Class members derive the formulas using the distance...

Find the height from afar. Teams role play as summer interns to find the height of a set of windows from the outside. Scholars must first determine how to find the height with the available tools. After determining a strategy involving...

Plant the fruits of trigonometry. Pairs work through the process of finding the best place to plant fruit trees on a piece of property. The scholars must take into consideration the location of the property and the solar zenith angle. To...

Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the...

All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....

Scientists don't have a ruler long enough to measure to the stars, so they rely on math. Scholars learn to calculate the distance from Earth to a star using the parallax method. They use angle measures from different perspectives to...

What's one more app? After reviewing how to calculate missing side lengths or angle measures in a right triangle, pupils create instructions for a phone app to do all of the tedious work. They must consider all nine cases of known...