Virginia Department of Education
Special Right Triangles and Right Triangle Trigonometry
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...
Radford University
Right Triangle Applications: Lessons 1 and 2
Use right triangles for more than just mathematical problems. The first two lessons of a unit ask pupils determine distances between cities by using the Pythagorean Theorem and a map. To cement understanding, learners use trigonometric...
Radford University
Pirate Attack
Arr ye matey, it's time for some trig. Learners first read up on the 2010 attack on the USS Nicholas by a group of pirates and the testimony of one of the witnesses. They use right triangle trigonometry to determine if the account is...
Radford University
Developing a Trigonometry Phone App
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...
EngageNY
Trigonometry and Complex Numbers
Complex numbers were first represented on the complex plane, now they are being represented using sine and cosine. Introduce the class to the polar form of a complex number with the 13th part of a 32-part series that defines the argument...
Radford University
Trouble in the Orchard
It's no fun catching a fungus. Scholars first investigate how the seasons affect the angle of the sun and the lengths of shadows. They then apply right triangle trigonometry to determine the height of trees based on their shadows to...
NASA
The Robotic Arm
Working as teams, class members try to rescue an astronaut using the shuttle arm on a TI-Nspire simulation. Teams must determine the different angle measures in order to reach the stranded astronaut.
EngageNY
Special Triangles and the Unit Circle
Calculate exact trigonometric values using the angles of special right triangles. Beginning with a review of the unit circle and trigonometric functions, class members use their knowledge of special right triangles to find the value of...
Illustrative Mathematics
Two Wheels and a Belt
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...
NASA
The Lunar Lander – Ascending from the Moon
What angle? Groups determine the height of the lunar lander as it ascends from the surface of the moon and calculate the angle of elevation of the lunar lander at specific times and distances. The provided series of questions lead the...
EngageNY
Complex Numbers and Transformations
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
Curated OER
Access Ramp
Just about every public building that your high schoolers 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...
EngageNY
Law of Sines
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
EngageNY
Putting the Law of Cosines and the Law of Sines to Use
Use the Law of Cosines and the Law of Sines to solve problems using the sums of vectors. Pupils work on several different types of real-world problems that can be modeled using triangles with three known measurements. In the process,...