Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...

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...

The topic of trigonometric ratios is often covered with loads of rote memorization baked into the activity. This activity set, however, leans more on using similar triangles and discovery learning to help young geometers develop a deeper...

What starts as a basic question of division and remainders quickly turns abstract in this question of related ratios and radii. The class works to surround a central coin with coins of the same and different values, then develops a...

Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....

If you have ever injured your shoulder, you know it takes a while to improve your arm's range of motion. In this real-world example, young mathematicians gain insight into the world of physical therapy while they analyze a case study...

Just about every public building that your students are familiar with has an access ramp which complies with ADA requirements. As it turns out, designing such a ramp is an excellent activity to incorporate slope, the Pythagorean Theorem,...

Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...

"Fore!" All right, no one really yells this out in miniature golf, but this well-defined activity will have your charges using lots of numbers in their unique design of a miniature golf hole. Included in the activity criteria is the...