Understanding the connection between Right Triangle Trigonometry and the Unit Circle by measuring and physically manipulating right triangles within a circle of radius 1 decimeter. This activity is optimal if you print the page with the One Decimeter ruler and six triangles on colored card stock paper. However, it will also work if all pages are printed on standard printer paper. 1. Print out one copy of each of the following pages. 2. Carefully and accurately cut out the One Decimeter ruler and the six right triangles. 3. Grab a pen or pencil, a calculator, and a straight edge if you have one (not required, but useful). 4. Now you are ready to follow along with the video guide. 0 One Decimeter .1 .2 3 4 5 6 7 8 9 30 15 45 45 60 75 1.0 40 20 10 50 70 80 Degree Radian 0 10 15 20 30 40 45 50 60 70 75 80 Angle 90 Data Sheet for Measuring Triangles Length of sides in decimeters Approx. Approx. Adjacent Opposite Hyp. Cosine Adj Measure Measure Measure Hyp Exact Exact Sine Opp Hyp Sine Cosine Opp Adj Hyp Hyp C2021 OPEN Global Village, Original Peoples Education Network, Inc. a 501(c)(3) NGO Educational non-profit organization Creating opportunity for Indigenous Human Development for the benefit of Individuals, Families and Society as a whole.