Click on the Green Flag. The mouse will draw a right triangle.The smaller of the three angles is set to 35º. The ratio of the side opposite the 35º angle to the hypotenuse is defined as the sine of 35º. The mouse will draw 10 right triangles and show that for every triangle, large or small, the sine of 35º is a constant.
We know that π equals the ratio of the circumference to the diameter of ANY circle. For all circles, π is a constant. No matter how small (atomic radius) or large (radius of 1 lightyear), the ratio of circumference to diameter is constant (π). The trigonometric functions (sine, cosine, and tangent) are usually introduced by looking at the relationships between the angles and sides of a right triangle. In my experience, students don't view the trig relationships as constants for a given angle.
